d & f – block – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Main chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas. Simulator Previous Years AIEEE/JEE Main Question
Q. In context with the transition elements, which of the following statements is incorrect? (1) In the highest oxidation states of the first five transition elements (Sc to Mn), all the 4s and 3d electrons are used for bonding. (2) Once the d5 configuration is exceeded, the tendency to involve all the 3d electrons in bonding decreases. (3) In addition to the normal oxidation states, the zero oxidation state is also shown by these elements in complexes. (4) In the highest oxidation states, the transition metal show basic character and form cationic complexes. [AIEEE-2009]

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Sol. (4)

Q. Iron exhibits +2 and +3 oxidation states. Which of the following statements about iron is incorrect ? (1) Ferrous compounds are more easily hydrolysed than the corresponding ferric compounds. (2) Ferrous oxide is more basic in nature than the ferric oxide. (3) Ferrous compounds are relatively more ionic than the corresponding ferric compounds. (4) Ferrous compounds are less volatile than the corresponding ferric compounds. [AIEEE-2012]

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Sol. (1)

Q. Consider the following reaction : $\mathrm{xMnO}_{4}^{-}+\mathrm{yC}_{2} \mathrm{O}_{4}^{2-}+\mathrm{zH}^{+} \rightarrow \mathrm{xMn}^{2+}+2 \mathrm{yCO}_{2}+\frac{\mathrm{Z}}{2} \mathrm{H}_{2} \mathrm{O}$ The values of x, y and z in the reaction are respectively :- (1) 5,2 and 16 (2) 2,5 and 8 (3) 2, 5 and 16 (4) 5,2 and 8 [JEE MAIN-2013]

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Sol. (3)

Q. Which of the following arrangements does not represent the correct order of the property stated against it ? (1) $\mathrm{V}^{2+}<\mathrm{Cr}^{2+}<\mathrm{Mn}^{2}<\mathrm{Fe}^{2+}$: paramagnetic behaviour (2) $\mathrm{Ni}^{2+}<\mathrm{Co}^{2+}<\mathrm{Fe}^{2+}<\mathrm{Mn}^{2+}$: ionic size (3)$\mathrm{Co}^{3+}<\mathrm{Fe}^{3+}<\mathrm{Cr}^{3+}<\mathrm{Sc}^{3+}$: stability in aqueous solution (4) $\mathrm{Sc}<\mathrm{Ti}<\mathrm{Cr}<$Mn : number of oxidation states [JEE MAIN-2013]

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Sol. (1)

Q. Potassium dichromate when heated with concentrated sulphuric acid and a soluble chloride, gives brown – red vapours of: (1) $\mathrm{CrO}_{3}$ (2) $\mathrm{Cr}_{2} \mathrm{O}_{3}$ (3) $\mathrm{CrCl}_{3}$ (4) $\mathrm{CrO}_{2} \mathrm{Cl}_{2}$ [JEE MAIN-2013, Online]

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Sol. (4) Explanation. $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+6 \mathrm{H}_{2} \mathrm{SO}_{4}+4 \mathrm{NaCl} \longrightarrow 2 \mathrm{KHSO}_{4}+4 \mathrm{NaHSO}_{4}+2 \mathrm{CrO}_{2} \mathrm{Cl}_{2}+3 \mathrm{H}_{2} \mathrm{O}$

Q. The element with which of the following outer electron configuration may exhibit the largest number of oxidation states in its compounds : (1) $3 \mathrm{d}^{7} 4 \mathrm{s}^{2}$ (2) $3 \mathrm{d}^{8} 4 \mathrm{s}^{2}$ ( 3) (3) $3 \mathrm{d}^{5} 4 \mathrm{s}^{2}$ (4) (4) $3 \mathrm{d}^{6} 4 \mathrm{S}^{2}$ [JEE MAIN-2013, Online]

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Sol. (3) Explanation $\mathrm{Mn} \longrightarrow \mathrm{Mn}^{+7}$

Q. When a small amount of $\mathrm{KMnO}_{4}$ is added to concentrated $\mathrm{H}_{2} \mathrm{SO}_{4}$a green oily compound is obtained which is highly explosive in nature. Compound may be: (1) $\mathrm{Mn}_{2} \mathrm{O}_{3}$ (2) MnSO $_{4}$ (3) $\mathrm{Mn}_{2} \mathrm{O}_{7}$ ( 4) $\mathrm{MnO}_{2}$ [JEE MAIN-2013, Online]

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Sol. (3) Explanation

Q. Which series of reactions correctly represents chemical relations related to iron and its compound? [JEE MAIN-2014]

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Sol. (2)

Q. The equation which is balanced and represents the correct product (s) is: [JEE MAIN-2014]

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Sol. (4)

Q. Which of the following is not formed when $\mathrm{H}_{2} \mathrm{S}$ reacts with acidic $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$solution ? ( 1) $\mathrm{K}_{2} \mathrm{SO}_{4}$ (2) $\mathrm{Cr}_{2}\left(\mathrm{SO}_{4}\right)_{3}$ (3) $\mathrm{S}$ (4) $\mathrm{CrSO}_{4}$ [JEE MAIN-2014, Online]

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Sol. (4)

Q. Copper becomes green when exposed to moist air for a long period. This is due to :- (1) the formation of a layer of cupric oxide on the surface of copper. (2) the formation of basic copper sulphate layer on the surface of the metal (3) the formation of a layer of cupric hydroxide on the surface of copper. (4) the formation of a layer of basic carbonate of copper on the surface of copper. [JEE MAIN-2014, Online]

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Sol. (4)

Q. Which one of the following exhibits the largest number of oxidation states ? (1) Mn(25) (2) V(23) (3) Cr (24) (4) Ti (22) [JEE MAIN-2014, Online]

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Sol. (1)

Q. How many electrons are involved in the following redox reaction? $\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+}+\mathrm{C}_{2} \mathrm{O}_{4}^{2-} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}+\mathrm{CO}_{2}$ (Unbalanced) (1) 3 (2) 4 (3) 5 (4) 6 [JEE MAINS-2014,Online]

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Sol. (4)

Q. Amongst the following, identify the species with an atom in +6 oxidation state: (1) $\left[\mathrm{MnO}_{4}\right]^{-}$ (2) $\left[\mathrm{Cr}(\mathrm{CN})_{6}\right]^{3-}$ (3) $\mathrm{Cr}_{2} \mathrm{O}_{3}$ (4) $\mathrm{CrO}_{2} \mathrm{Cl}_{2}$ [JEE MAIN-2014, Online]

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Sol. (4)

Q. Match the catalysts to the correct processes :- (1) A-ii, B-iii, C-iv, D-i (2) A-iii, B-i, C-ii, D-iv (3) A-iii, B-ii, C-iv, D-i (4) A-ii, B-i, C-iv, D-iii [JEE MAIN-2015]

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Sol. (4)

Q. Which of the following statements is false :- (1) has a Cr – O – Cr bond (2) is tetrahedral in shape (3) $\mathrm{Na}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ is a primary standard in volumetry (4) $\mathrm{Na}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ is less soluble than $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ [JEE MAIN-2015, Online]

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Sol. (3)

Polymer – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Main chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas.     Simulator   Previous Years AIEEE/JEE Main Questions
Q. Buna–N synthetic rubber is a copolymer of :- [AIEEE-2009]

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Sol. (1) Buna-N is actually abbrebiated form, where Bu represents 1, 3-butadiene, Na represents sodium and N represents nitrile (acrylonitrile). Thus, Buna-N is a copolymer of 1, 3-butadiene and acrylonitrile usually copolymer of 1, 3-butadiene, and acrylonitrile usually ploymerise in the presence of sodium.

Q. The polymer containing strong intermolecular forces e.g. hydrogen bonding, is :- (1) natural rubber (2) teflon (3) nylon 6, 6 (4) polystyrene [AIEEE-2010]

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Sol. (3)

Q. Thermosetting polymer, Bakelite is formed by the reaction of phenol with :- (1) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CHO}$ (2) $\mathrm{CH}_{3} \mathrm{CHO}$ (3) HCHO (4) HCOOH [AIEEE-2011]

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Sol. (3) Bakelite is a thermosetting polymer formed by the condensation reaction of phenol with HCHO in the presense of conc. $\mathrm{H}_{2} \mathrm{SO}_{4}$ It is thus, a cross-linked polymer in which condesation takes place at O- and p- positions So HCHO is the corerect option.

Q. The species which can best serve as an initiator for the cationic polymerization is :- (1) BuLi (3) HNO $_{3}$ (4) $\mathrm{AlCl}_{3}$ [AIEEE-2012]

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Sol. (4) Electron – deficient species (Lawis acid) like $\mathrm{AlCl}_{3}, \mathrm{BF}_{3}$ etc. are is used as initiator for cationic polymerisation.

Q. Which one is classified as a condensation polymer? (1) Teflon (2) Acrylonitrile (3) Dacron (4) Neoprene [JEE-Main 2014]

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Sol. (3)

Q. Which one of the following structures represents the neoprene polymer :- [JEE-Main(Online) – 2015]

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Sol. (3)

Q. Which polymer is used in the manufacture of paints and lacquers ? (1) Polypropene (2) Poly vinyl chloride (3) Bakelite (4) Glyptal [JEE- Main – 2015]

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Sol. (4)

Q. Which of the following statements about low density polythene is FALSE ? (1) It is used in the manufacture of buckets, dust-bins etc. (2) Its synthesis requires high pressure (3) It is a poor conductor of electricity (4) Its synthesis requires dioxygen or a peroxide initiator as a catalyst. [JEE Main 2016]

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Sol. (1) Low density polythene : It is obtained by the polymerisation of ethene under high presure of 1000-2000 atm. at a temp. of 350 K to 570 K in the pressure of traces of dioxygen or a peroxide

Q. Assertion : Rayon is a semisynthetic polymer whose properties are better than natural cotton. Reason : Mechanical and aesthetic properties of cellulose can be improved by acetylation. (1) Both assertion and reason are incorrect (2) Assertion is incorrect statement, but the reason is correct (3) Both assertion and reason are correct, but the reason is not the correct explanation for the assertion (4) Both assertion and reason are correct, and the reason is the correct explanation for the assertion [JEE Main (Online) 2016]

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Sol. (4)

Q. Which of the following polymers is synthesized using a free radical polymerization technique ? (1) Terylene (2) Teflon (3) Nylon 6,6 (4) Melamine polymer [JEE Main (Online) 2016]

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Sol. (2) [esquestion] The formation of which of the following polymers involves hydrolysis reaction ? (1) Nylon 6 (2) Bakelite (3) Nylon 6, 6 (4) Terylene #tag# [JEE – Main 2017]

Chemistry in Everyday Life – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Mains chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas. Simulator Previous Years AIEEE/JEE Mains Questions
Q. Which artificial sweetener contains chlorine ? (1) Aspartame (2) Saccharin (3) Sucralose (4) Alitame [JEE-Main(Online) – 2015]

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Sol. (3)

Q. Thiol group is present in :- (1)Methionine (2) Cytosine (3) Cystine (4) Cysteine [JEE-Main-2016]

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Sol. (4) Among 20 naturally occuring amino acids “Cysteine” has ‘– SH’ or thiol functional group.

Q. The distillation technique most suited for separating glycerol from spent-lye in the soap industry is: (1) Distillation under reduced pressure (2) Simple distillation (3) Fractional distillation (4) Steam distillation (Jee-Main-2016)

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Sol. (1) (1) Distillation under reduced pressure. Glycerol $\left(\mathrm{B} . \mathrm{P} .290^{\circ} \mathrm{C}\right)$ is separated from spent lye in the soap industry by distillation under reduced pressure, as for simple distillation very high temperature is required which might decompose the component.

Q. The predominant form of histamine present in human blood is $\left(\mathrm{pK}_{\mathrm{a}}\right.$, Histidine = 6.0) (1) (2) (3) (4)

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Sol. (3)

Carboxylic Acid – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Mains chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas. Simulator Previous Years AIEEE/JEE Mains Questions
Q. In the chemical reactions, (1) Nitrobenzene and chlorobenzene (2) Nitrobenzene and fluorobenzene (3) Phenol and benzene (4) Benzene diazonium chloride and fluorobenzene [AIEEE-2010]

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Sol. (4)

Q. In the chemical reactions (1) Fluorobenzene and phenol (2)Benzene diazonium chloride and benzonitrile (3) Nitrobenzene and chlorobenzene (4) Phenol and bromobenzene [AIEEE-2011]

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Sol. (2)

Q. Compound (A), $\mathrm{C}_{8} \mathrm{H}_{9} \mathrm{Br}$, gives a white precipitate when warmed with alcoholic $\mathrm{AgNO}_{3}$. Oxidation of (A) gives an acid (B), $\mathrm{C}_{8} \mathrm{H}_{6} \mathrm{O}_{4}$. (B) easily forms anhydride on heating. Identify the compound (A): [AIEEE-2013]

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Sol. (4) since B on heating gives anhydride so B is 1,2 dicarboxylic acid. It contains two Benzylic carbon at 1,2 position so on oxidation it produces 1, 2-dicarboxylic acid

Q. An organic compound A upon reacting with $\mathrm{NH}_{3}$ gives B. On heating, B gives C. C in presence of KOH reacts with $\mathbf{B} \mathbf{r}_{2}$ to give $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{NH}_{2}$. A is :- (1) $\mathrm{CH}_{3} \mathrm{COOH}$ (2) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{COOH}$ (4) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{COOH}$ [AIEEE-2013]

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Sol. (4)

Q. On heating an aliphatic primary amine with chloroform & ethenolic potassium hydroside the organic compound formed is (1) An alkyl cyanide (2) An alkyl isocyanide (3) an alkanol (4) an alkanediol [AIEEE-2014]

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Sol. (2) It is a carbyl amine reaction used for identification of primary amine also known as isocynide test because of offensive smell of isocynide.

Q. In the reaction (1) Ethylene (2) Acetyl chloride (3) Acetaldehyde (4) Acetylene. [AIEEE-2014]

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Sol. (1)

Q. In the presence of a small amount of phosphorous, aliphatic carboxylic acids react with chlorine or bromine to yield a compound in which  – hydrogen has been replaced by halogen. This reaction is known as : (1) Etard reaction (2) Hell – Volhard – Zelinsky reaction (3) Wolff – Kischner reaction (4) Rosenmund reaction [JEE(Main)-2015]

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Sol. (2)

Q. In the Hofmann bromamide degradation reaction, the number of moles of NaOH and $\mathrm{Br}_{2}$ used per mole of amine produced are : [JEE(Main)-2016]

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Sol. (1)

Q. The major product obtained in the following reaction is :- [JEE – Main 2017]

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Sol. (1) DIBAL – H is electrophilic reducing agent reduces cynide, esters, lactone, amide, carboxylic acid into corresponding Aldehyde (partial reduction)

Q. Sodium salt of an organic acid ‘X’ produces effervescence with conc. $\mathrm{H}_{2} \mathrm{SO}_{4}$. ‘X’ reacts with the acidified aqueous CaCl2 solution to give a white precipitate which decolourises acidic solution of $\mathrm{KMnO}_{4}$. ‘X’ is :- (1) $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{COONa}$ (2) HCOONa (3) CH3COONa (4) $\mathrm{Na}_{2} \mathrm{C}_{2} \mathrm{O}_{4}$ [JEE – Main – 2017]

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Sol. (4)

Q. Which of the following compounds will be suitable for Kjeldahl’s method for nitrogen estimation ? [JEE(Main)-2018]

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Sol. (1) Kjeldahl’s is suitable for Aniline. This method is used for quantitative analysis of N compound in organic substance $\left(\mathrm{NH}_{3} / \mathrm{NH}_{4}^{+}\right) .$

Carbonyl Compounds – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Mains chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas. Simulator   Previous Years AIEEE/JEE Mains Questions
Q. Which of the following on heating with aqueous KOH, produces acetaldehyde ? (1) $\mathrm{CH}_{2} \mathrm{ClCH}_{2} \mathrm{Cl}$ (2) $\mathrm{CH}_{3} \mathrm{CHCl}_{2}$ (3) $\mathrm{CH}_{3} \mathrm{COCl}$ (4) $\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{Cl}$ [AIEEE-2009]

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Sol. (2)

Q. In Cannizzaro reaction given below :- $2 \mathrm{Ph} \mathrm{CHO}$ $\mathrm{PhCH}_{2} \mathrm{OH}+\mathrm{PhCO}_{2}^{\Theta}$ the slowest step is :- (1) The abstraction of proton from the carboxylic group (2) The deprotonation of $\mathrm{CH}_{2} \mathrm{OH}$ (3) The attack of $: \stackrel{\ominus}{\mathrm{O}} \mathrm{H}$ at the carboxyl group (4) The transfer of hydride to the carbonyl group [AIEEE-2009]

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Sol. (4)

Q. One mole of a symmetrical alkene on ozonolysis gives two moles of an aldehyde having a molecular mass of 44 u. The alkene is :- (1) Ethene (2) Propene (3) 1-Butene (4) 2-Butene [AIEEE-2010]

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Sol. (4)

Q. Ozonolysis of an organic compound gives formaldehyde as one of the products. This confirms the presence of :- (1) An isopropyl group (2) An acetylenic triple bond (3) Two ethylenic double bonds (4) A vinyl group [AIEEE-2011]

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Sol. (4)

Q. Ozonolysis of an organic compound ‘A’ produces acetone and propionaldehyde in equimolar mixture. Identify ‘A’ from the following compounds : – (1) 2-Methyl – 1- pentene (2) 1-Pentene (3) 2-Pentene (4) 2-Methyl-2-pentene [AIEEE-2011]

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Sol. (4)

Q. Trichloroacetaldehyde was subjected to Cannizzaro’s reaction by using NaOH. The mixture of the products contains sodium trichloroacetate and another compound. The other (1) 2,2,2–Trichloropropanol (2) Chloroform (3) 2,2,2–Trichloroethanol (4) Trichloromethanol [AIEEE-2011]

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Sol. (3)

Q. Silver Mirror test is given by which one of the following compounds? (1) Formaldehyde (2) Benzophenone (3) Acetaldehyde (4) Acetone [AIEEE-2011]

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Sol. (1,3)

Q. In the given transformation, which of the following is the most appropriate reagent ? (1) $\mathrm{NaBH}_{4}$ (2) $\mathrm{NH}_{2} \mathrm{NH}_{2}, \stackrel{\ominus}{\mathrm{O}} \mathrm{H}$ (3) Zn – Hg / HCl $(4) \mathrm{Na}, \mathrm{Liq.NH}_{3}$ [AIEEE-2012]

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Sol. (2)

Q. Iodoform can be prepared from all except :- (1) Isobutyl alcohol (2) Ethyl methyl ketone (3) Isopropyl alcohol (4) 3-Methyl–2–butanone [AIEEE-2012]

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Sol. (1)

Q. A compound with molecular mass 180 is acylated with $\mathrm{CH}_{3} \mathrm{COCl}$ to get a compound with molecular mass 390. The number of amino groups present per molecule of the former compound is :- (1) 2 (2) 5 (3) 4 (4) 6 [JEE(Main)-2013]

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Sol. (2) 180 molecular mass after acylation gives compound of molecular mass 390. Change in molecular mass = 390 – 180 = 210 so number of $\mathrm{NH}_{2}$= $\frac{210}{42}$ = 5 group

Q. The major organic compound formed by the reaction of 1, 1, 1–trichloroethane with silver powder is :- (1)2-Butyne (2) 2-Butene (3) Acetylen (4) Ethene [JEE(Main)-2014]

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Sol. (1)

Q. The most suitable reagent for the conversion of $\mathrm{R}-\mathrm{CH}_{2}-\mathrm{OH} \rightarrow \mathrm{R}-\mathrm{CHO}$ is :- (1) $\mathrm{CrO}_{3}$ (2) PCC (Pyridinium chlorochromate) (3) $\mathrm{KMNO}_{4}$ (4) $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ [JEE(Main)-2014]

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Sol. (2) PCC is milder oxidising agent, oxidises only into aldehyde.

Q. A compound A with molecular formula $\mathrm{C}_{10} \mathrm{H}_{13} \mathrm{Cl}$ gives a white precipitate on adding silver nitrate solution. A on reacting with alcoholic KOH gives compound B as the main product. B on ozonolysis gives C and D. C gives Cannizaro reaction but not aldol condensation. D gives aldol condensation but not Cannizaro reaction. A is : #tag [JEE(Main)-2015]

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Sol. (2)

Q. In the reaction sequence ; the product B is:- (1) $\mathrm{CH}_{3}-\mathrm{CH}=\mathrm{CH}-\mathrm{CHO}$ (2) $\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{3}$ (3) $\mathrm{CH}_{3}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{CH}_{2}-\mathrm{OH}$ (4) [JEE(Main)-2015]

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Sol. (1)

Q. Which compound would give 5-keto-2-methyl hexanal upon ozonlysis? [JEE(Main) 2015]

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Sol. (4)

Biomolecule – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Mains chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas. Simulator   Previous Years AIEEE/JEE Main Questions
Q. The two functional groups present in a typical carbohydrate are :- (1) >C = O and –OH (2) –OH and –CHO (3) –OH and –COOH (4) –CHO and –COOH AIEEE-2009

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Sol. (2)

Q. Biurest test is not given by :- (1) proteins (2) carbohydrates (3) polypeptides (4) urea AIEEE-2010

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Sol. (2)

Q. The presence or absence of hydroxy group on which carbon atom of sugar differentiates RNA and DNA? (1) 3rd (2) 4th (3) 1st (4) 2nd AIEEE-2011

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Sol. (4)

Q. The change in the optical rotation of freshly prepared solution of glucose is known as :- (1) tautomerism (2) racemisation (3) specific rotation (4) mutarotation AIEEE-2011

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Sol. (4)

Q. Which one of the following statements is correct ? (1) All amino acids except glutamic acid are optically active (2) All amino acids except lysine are optically active (3) All amino acids are optically active (4) All amino acids except glycine are optically active AIEEE-2012

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Sol. (4)

Q. Synthesis of each molecule of glucose in photosynthesis involves :- (1) 18 molecules of ATP (2) 10 molecules of ATP (3) 8 molecules of ATP (4) 6 molecules of ATP JEE Main -2013

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Sol. (1) Six rounds of the Calvin cycle are required, because one carbon atom is reduced in each round. Twelve molecules of ATP are expended. An additional six molecular of ATP are spent in regenerating ribulose-1, 5-biphosphate $6 \mathrm{CO}_{2}+18 \mathrm{ATP}+12 \mathrm{NADPH}+12 \mathrm{H}_{2} \mathrm{O} \rightarrow$ $\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+18 \mathrm{ADP}+18 \mathrm{P}_{\mathrm{i}}+12 \mathrm{NADP}+6 \mathrm{H} \oplus$ Reference : NCERT 11th class chapter-13 (Photosynthesis Pg. 217, 218 in higher plants. Calvin cycle where sugar is synthesised is as follows : The Calvin cycle proceeds in three stages (1) carboxylation, during which $\mathrm{CO}_{2}$ combines with ribulose-1.5-bisphosphate (2) reduction, during which carbohydrate is formed at the expense of the photochemically made ATP and NADPH and (3) regeneration during which the $\mathrm{CO}_{2}$ acceptor ribulose-1,5-bisphosphate is formed again so that the cylcle continues. It might help you to understand all of this if we look at what goes in and what comes out of the Calvin cycle.

Q. Which one of the following bases is not present in DNA ? (1) Cytosine (2) Thymine (3) Quinoline (4) Adenine JEE-Main 2014

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Sol. (3) All cytosine, thymine and adenine are present in DNA. Only quinoline is not present in DNA.

Q. Which of the vitamins given below is water soluble? (1) Vitamin E (2) Vitamin K (3) Vitamin C (4) Vitamin D JEE-Main 2015

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Sol. (3) Vitamine C is soluble in water due to H-Bonding & all other vitamines given in question are fat soluble.

Q. Complete hydrolysis of starch gives : (1) glucose and fructose in equimolar amounts (2) glucose only (3) galactose and fructose in equimolar amounts (4) glucose and galactose in equimolar amounts JEE-Main(Online) – 2015

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Sol. (2) Starch is polymer of Glucose

Q. Accumulation of which of the following molecules in the muscles occurs as a result of vigorous exercise :- (1) Pyruvic acid (2) L-lactic acid (3) Glycogen (4) Glucose JEE-Main(Online) – 2015

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Sol. (2)

Q. Consider the following sequence for aspartic acid: The pI (isoelectric point) of aspartic acid is : (1) 1.88 (2) 2.77 (3) 3.65 (4) 5.74 JEE-Main(Online) – 2016

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Sol. (4)

Q. Observation of “Rhumann’s purple” is a confirmatory test for the presence of : (1) Starch (2) Reducing sugar (3) Cupric ion (4) Protein JEE-Main(Online) – 2017

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Sol. (1)

Q. Which of the following compounds will behave as a reducing sugar in an aqueous KOH solution ? JEE-Main 2017

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Sol. (1) (1) Ester in presence of Aqueous KOH solution give SNAE reaction so following reaction takes place

Alcohol & Ether – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Mains chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas. Simulator Previous Years AIEEE/JEE Mains Questions
Q. The number of stereoisomers possible for a compound of the molecular formula (1) 4        (2) 6         (3) 3           (4) 2 AIEEE-2009

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Sol. (1)

Q. A liquid was mixed with ethanol and a drop of concentrated $\mathrm{H}_{2} \mathrm{SO}_{4}$ was added. A compound with a fruity smell was formed. The liquid was :- (1) $\mathrm{CH}_{3} \mathrm{COCH}_{3}$ (2) $\mathrm{CH}_{3} \mathrm{COOH}$ (3) $\mathrm{CH}_{3} \mathrm{OH}$ (4) HCHO AIEEE-2009

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Sol. (2)

Q. From amongst the following alcohols the one that would react fastest with conc. HCl and anhydrous $\mathrm{ZnCl}_{2}$, is :- (1) 1–Butanol (2) 2–Butanol (3) 2–Methylpropan–2–ol (4) 2–Methylpropanol AIEEE-2010

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Sol. (3)

Q. Consider the following reaction : $\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}+\mathrm{H}_{2} \mathrm{SO}_{4} \rightarrow$ Produce Among the following, which one cannot be formed as a product under any conditions ? (1) Ethyl-hydrogen sulphate (2) Ethylene (3) Acetylene (3) Diethyl ethe AIEEE-2011

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Sol. (3)

Q. Iodoform can be prepared from all except :- (1) Isobutyl alcohol (2) Ethyl methyl ketone (3) Isopropyl alcohol (4) 3-Methyl–2–butanone AIEEE-2012

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Sol. (1)

Q. An unknown alcohol is treated with the “Lucas reagent’ to determine whether the alcohol is primary, secondary or tertiary. Which alcohol reacts fastest and by what mechanism :- (1) secondary alcoholby SN $^{1}$ (2) tertiary alcohol by SN $^{1}$ (3) secondary alcoholby SN $^{2}$ (4) tertiary alcohol by SN $^{2}$ AIEEE-2013

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Sol. (2)

Q. The most suitable reagent for the conversion of $\mathrm{R}-\mathrm{CH}_{2}-\mathrm{OH} \rightarrow \mathrm{R}-\mathrm{CHO}$ is : (1) $\mathrm{CiO}_{3}$ (2) PCC (Pyridinium chlorochromate) (3) KMNO $_{4}$ (4) $\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}$ Jee-Main-2014

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Sol. (2)

Q. Allyl phenyl ether can be prepared by heating: (1) $\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{2}-\mathrm{Br}+\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{ONa}$ (2) $\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{CH}=\mathrm{CH}-\mathrm{Br}+\mathrm{CH}_{3}-\mathrm{ONa}$ (3) $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{Br}+\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{CH}_{2}-\mathrm{ONa}$ (4) $\mathrm{CH}_{2}=\mathrm{CH}-\mathrm{Br}+\mathrm{C}_{6} \mathrm{H}_{5}-\mathrm{CH}_{2}-\mathrm{ONa}$ Jee-Main-2014

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Sol. (1)

Q. In the Victor-Meyer’s test, the colour given by $1^{\circ}, 2^{\circ}$ and $3^{\circ}$ alcohols are respectively :- (1) Red, blue, colourless (2) Colourless, red, blue (3) Red, blue, violet (4) Red, colourless, blue Jee-Main-2014

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Sol. (1)

Q. Williamson synthesis of ether is an example of (1) Nucleophilic addition (2) Electrophilic substitution (3) Nucleophilic substitution (4) Electrophilic addition Jee-Main-2014

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Sol. (3) Nucleophilic substitution

Q. Phenol on treatment with $\mathrm{CO}_{2}$ in the presence of NaOH followed by acidification produces compound X as the major product. X on treatment with $\left(\mathrm{CH}_{3} \mathrm{CO}\right)_{2} \mathrm{O}$ in the presence of catalytic amount of $\mathrm{H}_{2} \mathrm{SO}_{4}$ produces : Jee-Main-2018

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Sol. (4)

Q. Phenol reacts with methyl chloroformate in the presence of NaOH to form product A. A reacts with $\mathrm{Br}_{2}$ to form product B. A and B are respectively : Jee-Main-2018

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Sol. (2)

Salt Analysis – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Main chapter wise questions of Chemistry will help the JEE aspirants in realising the question pattern as well as help in analysing weak & strong areas.   Simulator   Previous Years AIEEE/JEE Mains Questions
Q. The products obtained on heating LiNO3 will be :- (1) $\mathrm{LiNO}_{2}+\mathrm{O}_{2}$ (2) $\mathrm{Li}_{2} \mathrm{O}+\mathrm{NO}_{2}+\mathrm{O}_{2}$ (3) $\mathrm{Li}_{3} \mathrm{N}+\mathrm{O}_{2}$ (4) $\mathrm{Li}_{2} \mathrm{O}+\mathrm{NO}+\mathrm{O}_{2}$ AIEEE-2011

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Sol. (2) $\mathrm{LiNO}_{3} \longrightarrow \mathrm{Li}_{2} \mathrm{O}+\mathrm{NO}_{2}+\mathrm{O}$

Q. What is the best description of the change that occurs when $\mathrm{Na}_{2} \mathrm{O}(\mathrm{s})$ is dissolved in water ? (1) Oxidation number of sodium decreases (2) Oxide ion accepts sharing in a pair of electrons (3) Oxide ion donates a pair of electrons (4) Oxidation number of oxygen increases AIEEE-2011

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Sol. (3) $\mathrm{Na}_{2} \mathrm{O}+\mathrm{HOH} \longrightarrow \mathrm{CaO}+\mathrm{CO}_{2}$

Q. Which of the following on thermal-decomposition yields a basic as well as an acidi oxide ? (1) $\mathrm{NH}_{4} \mathrm{NO}_{3}$ (2) NaNO $_{3}$ (3) $\mathrm{KClO}_{3}$ (4) $\mathrm{CaCO}_{3}$ AIEEE-2012

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Sol. (4) $\mathrm{CaCO}_{3} \longrightarrow \mathrm{CaO}+\mathrm{CO}_{2}$

Q. Fire extinguishers contain H2SO4 and which one of the following :- (1) $\mathrm{CaCO}_{3}$ (2) $\mathrm{NaHCO}_{3}$ and $\mathrm{Na}_{2} \mathrm{CO}_{3}$ (3) $\mathrm{Na}_{2} \mathrm{CO}_{3}$ (4) $\mathrm{NaHCO}_{3}$ JEE(Main)-2012 online-P-1

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Sol. (4) Fire extinguishers contain H2SO4 and NaHCO3

Q. Copper wire test for halogens is known as :- (1) Duma’s Test (2) Beilstein’s Test (3) Lasssigne’s Test (4) Liebig’s Test JEE(Main)-2012 online-P-2

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Sol. (2) Beilstein’s Test

Q. The standard potentials of $\mathrm{Ag}^{+} / \mathrm{Ag}, \mathrm{Hg}_{2}^{2+} / 2 \mathrm{Hg}, \mathrm{Cu}^{2+} / \mathrm{Cu}$ and $\mathrm{Mg}^{2+} /$ Mg electrodes are 0.80, 0.79, 0.34 and – 2.37 V, respectively. An aqueous solution which contains one mole per litre of the salts of each of the four metals is electrolyzed. With increasing voltage, the correct sequence of deposition of the metals at the cathode is :- (1) Cu, Hg, Ag only (2) Mg, Cu, Hg, Ag (3) Ag, Hg, Cu only (4) Ag, Hg, Cu, Mg [JEE(Main)-2012 online-P-3]

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Sol. (3)

Q. Beilstein test is used for estimation of which one of following elements ? (1) S (2) Cl (3) C and H (4) N JEE(Main)-2012 online-P-3

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Sol. (2) $5 \mathrm{Mn} \mathrm{O}_{4}^{-}+2 \mathrm{C}_{2} \mathrm{O}_{4}^{2-}+16 \mathrm{H}^{+} \longrightarrow 5 \mathrm{Mn}^{+2}+2 \mathrm{CO}_{2}+\frac{16}{2} \mathrm{H}_{2} \mathrm{O}$

Q. In the following balanced reaction, $\mathrm{XMnO}_{+}^{-}+\mathrm{YC}_{2} \mathrm{O}_{4}^{2-}+\mathrm{ZH}^{+}=\mathrm{XMn}^{2+}+2 \mathrm{YCO}_{2}+$ $\frac{\mathrm{Z}}{2} \mathrm{H}_{2} \mathrm{O}$ the values of X, Y and Z, respectively are :- JEE(Main)-2012 online-P-4

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Sol. (2)

Q. A metal M on heating in nitrogen gas gives Y. Y on treatment with $\mathrm{H}_{2} \mathrm{O}$ gives a colourless gas which when passed through $\mathrm{CuSO}_{4}$ solution gives a blue colour, Y is :- (1) $\mathrm{NH}_{3}$ (2) MgO (3) $\mathrm{Mg}_{3} \mathrm{N}_{2}$ (4) $\mathrm{Mg}\left(\mathrm{NO}_{3}\right)_{2}$ JEE(Main)-2012 online-P-4

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Sol. (3)

Q. Electrode potentials (E0) are given below : $\mathrm{Cu}^{+} / \mathrm{Cu}=+0.52 \mathrm{V}, \mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}=+0.77 \mathrm{V}$ $1 / 2 \mathrm{I}_{2}(\mathrm{s}) / \mathrm{I}^{-}=+0.54 \mathrm{V}, \mathrm{Ag}^{+} / \mathrm{Ag}=+0.88 \mathrm{V}$ Based on the above potentials, strnogest oxidizing agent will be : (1) $\mathrm{Cu}^{+}$ (3) $\mathrm{Ag}^{+}$ (4) $\mathrm{I}_{2}$ JEE(Main)-2013 online-P-1

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Sol. (3)

Q. Potassium dichromate when heated with concentrated sulphuric acid and a soluble chloride, gives brown – red vapours of: ( 1) $\mathrm{CrO}_{3}$ (2) $\mathrm{Cr}_{2} \mathrm{O}_{3}$ (3) $\mathrm{CrCl}_{3}$ (4) $\mathrm{CrO}_{2} \mathrm{Cl}_{2}$ JEE(Main)-2013 online-P-1

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Sol. (4)

Q. Given : $\overline{\mathrm{X}} \mathrm{Na}_{2} \mathrm{HAsO}_{3}+\mathrm{Y} \mathrm{NaBrO}_{3}+\mathrm{ZHCl} \rightarrow \mathrm{NaBr}+\mathrm{H}_{3} \mathrm{AsO}_{4}+\mathrm{NaCl}$ The values of X, Y and Z in the above redox reaction are respectively : (1) 2, 1, 3 (2) 3, 1, 6 (3) 2, 1, 2 (4) 3, 1, 4 JEE(Main)-2013 online-P-1

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Sol. (2) $3 \mathrm{Na}_{2} \mathrm{HAsO}_{3}+\mathrm{NaBrO}_{3}+6 \mathrm{HCl} \longrightarrow \mathrm{NaBr}+\mathrm{H}_{3} \mathrm{AsO}_{4}+\mathrm{NaCl}$

Q. Sodium Carbonate cannot be used in place of $\left(\mathrm{NH}_{4}\right)_{2} \mathrm{CO}_{3}$ for the identification of $\mathrm{Ca}^{2+}, \mathrm{Ba}^{2+}$ and $\mathrm{Sr}^{2+}$ ions (in group V) during mixture analysis because : (1) Sodium ions will react with acid radicals (2) Concentration of $\mathrm{CO}_{3}^{2-}$ ions is very low (3) Mg $^{2+}$ ions will also be precipitated (4) $\mathrm{Na}^{+}$ ions will interfere with the detection of $\mathrm{Ca}^{2+}, \mathrm{Ba}^{2+}, \mathrm{Sr}^{2+}$ ions JEE(Main)-2013 online-P-1

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Sol. (3) According to reactivity series Mg can be displaced by Na.

Q. Which of the following statements is incorrect? (1) $\mathrm{Fe}^{2+}$ ion also gives blood red colour with $\mathrm{SCN}^{-}$ ion (2) Cupric ion reacts with excess of ammonia solution to give deep blue colour of $\left[\mathrm{Cu}\left(\mathrm{NH}_{3}\right)_{4}\right]^{2+}$ ion. (3) $\mathrm{Fe}^{3+}$ ion gives blood red colour with $\mathrm{SCN}^{-}$ ion. (4) On passing $\mathrm{H}_{2} \mathrm{S}$ into $\mathrm{Na}_{2} \mathrm{ZnO}_{2}$ solution, a white ppt of ZnS is formed.

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Sol. (1) $\mathrm{Fe}^{+2}+\mathrm{SCN}^{-} \longrightarrow$ No colour

Q. Values of dissociation constant, $\mathrm{K}_{\mathrm{a}}$ are given as follows : (1) $\mathrm{NO}_{2}^{-}<\mathrm{CN}^{-}<\mathrm{F}^{-}$ (2) $\mathrm{F}^{-}<\mathrm{CN}^{-}<\mathrm{NO}_{2}^{-}$ (3) $\mathrm{NO}_{2}^{-}<\mathrm{F}^{-}<\mathrm{CN}^{-}$ (4) $\mathrm{F}^{-}<\mathrm{NO}_{2}^{-}<\mathrm{CN}^{-}$ JEE(Main)-2013 online-P-2

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Sol. (4) Order of basic strength according to Ka value. $\mathrm{CN}^{-}>\mathrm{NO}_{2}^{-}>\mathrm{F}^{-}$

Q. Identify incorrect statement (1) Copper (I) compounds are colourless except where colour results from charge transfer (2) Copper (I) compounds are diamagnetic (3) $\mathrm{Cu}_{2} \mathrm{S}$ is black (4) $\mathrm{Cu}_{2} \mathrm{O}$ is colourless JEE(Main)-2013 online-P-3

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Sol. (4) $\mathrm{Cu}_{2} \mathrm{O}$ is red.

Q. Given : $\mathrm{E}_{1 / 2 \mathrm{C}_{2} / \mathrm{Cl}^{-}}^{0}=1.36 \mathrm{V}, \mathrm{E}_{\mathrm{Cr}^{3+} / \mathrm{Gr}}^{0}=-0.74 \mathrm{V} ; \quad \mathrm{E}_{\mathrm{G}_{2} \mathrm{O}_{7}^{2-} / \mathrm{Cr}^{3+}}^{0}=1.33 \mathrm{V}, \mathrm{E}_{\mathrm{MnO}_{4}^{-} / \mathrm{Mn}^{2+}}^{0}=1.51 \mathrm{V}$ The correct order of reducing power of the species $\left(\mathrm{Cr}, \mathrm{Cr}^{3+}, \mathrm{Mn}^{2+} \text { and } \mathrm{Cl}^{-}\right)$ will be : JEE(Main)-2013 online-P-3 (1) $\mathrm{Mn}^{2+}<\mathrm{Cl}^{-}<\mathrm{Cr}^{3+}<\mathrm{Cr}$ (2) $\mathrm{Cr}^{3+}<\mathrm{Cl}^{-}<\mathrm{Mn}^{2+}<\mathrm{Cr}$ (3) $\mathrm{Cr}^{3+}<\mathrm{Cl}^{-}<\mathrm{Cr}<\mathrm{Mn}^{2+}$ (4) $\mathrm{Mn}^{2+}<\mathrm{Cr}^{3+}<\mathrm{Cl}^{-}<$

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Sol. (1) Order of reducing power acoording to E $\mathrm{Cr}>\mathrm{Cr}^{+3}>\mathrm{Cl}^{-}>\mathrm{Mn}^{+2}$

Q. Which one of the following cannot function as an oxidising agent ? (1) $\mathrm{NO}_{3}^{-}(\mathrm{aq})$ ( 2) $\mathrm{I}^{-}$ (3) $\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}$ ( 4) $\mathrm{S}_{(\mathrm{S})}$ JEE(Main)-2014 online_P-2

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Sol. (2) $\mathrm{I}^{-}$ has lowest oxidation state.

Q. Which of the following statements about $\mathrm{Na}_{2} \mathrm{O}_{2}$ is not correct ? (1) $\mathrm{Na}_{2} \mathrm{O}_{2}$ oxidises $\mathrm{Cr}^{3+}$ to $\mathrm{CrO}_{4}^{2-}$ in acid medium (2) It is diamagnetic in nature (3) It is the super oxide of sodium (4) It is a derivative of $\mathrm{H}_{2} \mathrm{O}_{2}$ JEE(Main)-2014 online_P-2

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Sol. (2) $\mathrm{Na}_{2} \mathrm{O}_{2}$ is peroxide

Q. Given :- $\mathrm{Fe}^{3+}(\mathrm{aq})+\mathrm{e}^{-} \rightarrow \mathrm{Fe}^{2+}(\mathrm{aq}) ; \mathrm{E}^{\circ}=+0.77 \mathrm{V}$ $\mathrm{A}^{3+}(\mathrm{aq})+3 \mathrm{e}^{-} \rightarrow \mathrm{Al}(\mathrm{s}) ; \mathrm{E}^{\circ}=-1.66 \mathrm{V}$ $\mathrm{Br}_{2}(\mathrm{aq})+2 \mathrm{e}^{-} \rightarrow 2 \mathrm{Br}^{-} ; \mathrm{E}^{\circ}=+1.09 \mathrm{V}$ Considering the electrode potentials, which of the following represents the correct order of reducing power? (1) $\mathrm{Al}<\mathrm{Fe}^{2+}<\mathrm{Br}^{-}$ (2) $\mathrm{Al}<\mathrm{Br}^{-}<\mathrm{Fe}^{2+}$ (3) $\mathrm{Fe}^{2+}<\mathrm{Al}<\mathrm{Br}^{-}$ $(4) \mathrm{Br}^{-}<\mathrm{Fe}^{2+}<\mathrm{Al}$ JEE(Main)-2014 online-P-2

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Sol. (4) Order of reducing power according to $\mathrm{E}^{\circ}$ $\mathrm{Br}^{-}<\mathrm{Fe}^{+2}<\mathrm{Al}$

Q. Consider the following equilibrium White precipitate of AgCl appears on adding which of the following? (1) $\mathrm{NH}_{3}$ (2) Aqueous NaCl (3) Aqueous $\mathrm{NH}_{4} \mathrm{Cl}$ (4) AqueousHNO $_{3}$ JEE(Main)-2014 online-P-2

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Sol. (4) $\left[\mathrm{Ag}\left(\mathrm{NH}_{3}\right)_{4}\right] \mathrm{Cl}+\mathrm{aqH} \mathrm{NO}_{3} \longrightarrow \mathrm{AgCl} \downarrow$

Q. Copper becomes green when exposed to moist air for a long period. This is due to :- (1) the formation of a layer of cupric oxide on the surface of copper. (2) the formation of basic copper sulphate layer on the surface of the metal (3) the formation of a layer of cupric hydroxide on the surface of copper. (4) the formation of a layer of basic carbonate of copper on the surface of copper. JEE(Main)-2014 online-P-3

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Sol. (4) $\mathrm{Cu} \frac{\text { Moist }}{\mathrm{air}}>\mathrm{CuCO}_{3} \cdot \mathrm{Cu}(\mathrm{OH})_{2}$

Q. The correct statement for the molecule, $\mathrm{CsI}_{3},$ is: (1) it contains $\mathrm{Cs}^{3+}$ and $\mathrm{I}^{-}$ ions (2) dit contains $\mathrm{Cs}^{3+}$ and $\mathrm{I}^{-}$ ions (3) it is a covalent molecule (4) it contains $\mathrm{Cs}^{+}$ and $\mathrm{I}_{3}^{-}$ ions JEE(Main)-2014

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Sol. (4) $\mathrm{CsI}_{3} \longrightarrow \mathrm{Cs}^{+}+\mathrm{I}_{3}^{-}$

Q. Which one of the following exhibits the largest number of oxidation states ? (1) Mn(25) (2) V(23) (3) Cr (24) (4) Ti (22) JEE(Main)-2014 online-P-3

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Sol. (1) Mn has maximum number of oxidation state.

Q. Hydrogen peroxide acts both as an oxidising and as a reducing agent depending upon the nature of the reacting species. In which of the following cases $\mathrm{H}_{2} \mathrm{O}_{2}$ acts as a reducing agent in acid medium ? :- JEE(Main)-2014 online-P-3 (1) $\mathrm{MnO}_{4}^{-}$ (2) $\mathrm{SO}_{3}^{2-}$ (3) KI (4) $\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}$

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Sol. (1) $\mathrm{H}_{2} \mathrm{O}_{2}$ acts as a reducing agent in acidic medium in pressure of $\mathrm{MnO}_{4}^{-}$

Q. Consider the reaction $\mathrm{H}_{2} \mathrm{SO}_{3(\mathrm{aq})}+\mathrm{Sn}_{(\mathrm{aq})}^{4+}+\mathrm{H}_{2} \mathrm{O}_{(\mathrm{l})} \rightarrow \mathrm{Sn}_{(\mathrm{aq})}^{2+}+\mathrm{HSO}_{4(\mathrm{aq})}^{-}+3 \mathrm{H}_{(\mathrm{aq})}^{+}$ Which of the following statements is correct? (1) $\mathrm{H}_{2} \mathrm{SO}_{3}$ is the reducing agent because it undergoes oxidation (2) $\mathrm{H}_{2} \mathrm{SO}_{3}$ is the reducing agent because it undergoes reduction (3) $\mathrm{Sn}^{4+}$ is the reducing agent because it undergoes oxidation (4) $\mathrm{Sn}^{4+}$ is the oxidizing agent because it undergoes oxidation JEE(Main)-2014 online-P-4

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Sol. (1)

Q. How many electrons are involved in the following redox reaction ? $\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}+\mathrm{Fe}^{2+}+\mathrm{C}_{2} \mathrm{O}_{4}^{2-} \rightarrow \mathrm{Cr}^{3+}+\mathrm{Fe}^{3+}+\mathrm{CO}_{2}$ (Unbalanced) (1) 3 (2) 4 (3) 5 (4) 6 JEE(Main)-2014 online-P-4

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Sol. (4) $6 e^{-}$ are involved in this reaction

Q. Amongst the following, identify the species with an atom in +6 oxidation state: (1) $\left[\mathrm{MnO}_{4}\right]^{-}$ (2) $\left[\mathrm{Cr}(\mathrm{CN})_{6}\right]^{3-}$ (3) $\mathrm{Cr}_{2} \mathrm{O}_{3}$ (4) $\mathrm{Cr} \mathrm{o}_{2} \mathrm{Cl}_{2}$ JEE(Main)-2014 online-P-4

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Sol. (4) $\mathrm{CrO}_{2} \mathrm{Cl}_{2} \mathrm{x}+(-4)+(-2)=0$ $\mathrm{x}=+6$

Q. Which of the following salts is the most basic in aqueous solution ? ( 1) $\mathrm{CH}_{3} \mathrm{COOK}$ ( 2) $\mathrm{FeCl}_{3}$ (3) $\mathrm{Pb}\left(\mathrm{CH}_{3} \mathrm{COO}\right)_{2}$ (4) $\mathrm{Al}(\mathrm{CN})_{3}$ JEE(Main)-2018

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Sol. (1)

Surface Chemistry – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Main chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas.   Simulator   Previous Years AIEEE/JEE Main Questions
Q. Which of the following statements is incorrect regarding physisorptions ? (1) Under high pressure it results into multi molecular layer on adsorbent surface (2) Enthalpy of adsorption $\left(\Delta \mathrm{H}_{\text {adsorption }}\right)$ is low and positive (3) It occurs because of Van der Waal’s forces (4) More easily liquefiable gases are adsorbed readi AIEEE-2009

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Sol. (2) $\Delta \mathrm{H}$ is negative

Q. According to Freundlich adsorption isotherm, which of the following is correct ? (1) $\frac{\mathrm{x}}{\mathrm{m}} \propto \mathrm{p}^{0}$ (2) $\frac{\mathrm{x}}{\mathrm{m}} \propto \mathrm{p}^{1}$ (3) $\frac{\mathrm{x}}{\mathrm{m}} \propto \mathrm{p}^{1 / \mathrm{n}}$ (4) All the above are correct for different ranges of pressure AIEEE-2012

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Sol. (4)

Q. The coagulating power of electrolytes having ions $\mathrm{Na}^{+}, \mathrm{Al}^{3+}$ and $\mathrm{Ba}^{2+}$ for aresenic sulphide sol increases in the order :- (1) $\mathrm{Al}^{3+}<\mathrm{Ba}^{2+}<\mathrm{Na}^{+}$ (2) $\mathrm{Na}^{+}<\mathrm{Ba}^{2+}<\mathrm{Al}^{3+}$. (3) $\mathrm{Ba}^{2+}<\mathrm{Na}^{+}<\mathrm{Al}^{3+}$ (4) $\mathrm{Al}^{3+}<\mathrm{Na}^{+}<\mathrm{Ba}^{2+}$ JEE-Main 2013

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Sol. (2) According to hardley schuzle rule

Q. For a linear plot of log(x/m) versus log p in a Freundlich adsorption isotherm, which of the following statements is correct ? (k and n are constants) (1) log (1/n) appears as the intercept (2) Both k and 1/n appear in the slope term (3) 1/n appears as the intercept (4) Only 1/n appears as the slope JEE-Main 2016

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Sol. (4) According to Freundlich isotherm

Q. The Tyndall effect is observed only when following conditions are satisfied :- (a) The diameter of the dispersed particles is much smaller than the wavelength of the ligh used. (b) The diameter of the dispersed particle is not much smaller than the wavelength of the light used. (c) The refractive indices of the dispersed phase and dispersion medium are almost similar in magnitude. (d) The refractive indices of the dispersed phase and dispersion medium differ greatly in magnitude. (1) (a) and (d) (2) (b) and (d) (3) (a) and (c) (4) (b) and (c) JEE – Main – 2017

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Sol. (2) As per NCERT book (fact)

Solid State – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Main chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas.   Simulator Previous Years AIEEE/JEE Mains Questions
Q. The edge length of a face centered cubic cell of an ionic substance is 508 pm. If the radius of the cation is 110 pm, the radius of the anion is :- (1) 144 pm (2) 288 pm (3) 398 pm (4) 618 pm Aieee-10

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Sol. (1) radius of cation = 110 pm if cation present 2n OV $a=2\left(r_{+}+r_{-}\right)$ 508 = 2[110 + x] x = 144 pm

Q. Percentages of free space in cubic close packed structure and in body centered packed structure are respectively :- (1) 48% and 26% (2) 30% and 26% (3) 26% and 32% (4) 32% and 48% Aieee-10

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Sol. (3) Theory Based

Q. Copper crystallises in fcc lattice with a unit cell edge of 361 pm. The radius of copper atom is:- (1) 181 pm (2) 108 pm (3) 128 pm (4) 157 pm Aieee-11 / JEE-Main-ONLINE 2013

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Sol. (3)

Q. In a face centred cubic lattice, atom A occupies the corner positions and atom B occupies the face centre positions. If one atom of B is missing from one of the face centred points, the formula of the compound is :- (1) $\mathrm{A}_{2} \mathrm{B}_{3}$ ( 2) $\mathrm{A}_{2} \mathrm{B}_{5}$ (3) $\mathrm{A}_{2} \mathrm{B}$ (4) $\mathrm{AB}_{2}$ Aieee-11 / JEE-Main-ONLINE 2014

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Sol. (2)

Q. Lithium forms body centred cubic structure. The length of the side of its unit cell is 351 pm. Atomic radius of the lithium will be :- (1) 152 pm (2) 75 pm (3) 300 pm (4) 240 pm Aieee-12

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Sol. (1)

Q. The radius of a calcium ion is 94 pm and of the oxide ion is 146 pm. The possible crystal structure of calcium oxide will be :- (1) Octahedral        (2) Tetrahedral          (3) Pyramidal           (4) Trigonal Jee-Main (online)-12

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Sol. (1)

Q. Ammonium chloride crystallizes in a body centred cubic lattice with edge length of unit cell of 390 pm. If the size of chloride ion is180 pm, the size of ammonium ion would be: (1) 158 pm (2) 174 pm (3) 142 pm (4) 126 pm Jee-Main (online)-12

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Sol. (1)

Q. A solid has ‘bcc’ structure. If the distance of nearest approach between two atoms is 1.73 Å, the edge length of the cell is :- (1) 314.20 pm (2) 216 pm (3) 200 pm (4) 1.41 pm Jee-Main (online)-12

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Sol. (3)

Q. Among the following the incorrect statement is :- (1) Density of crystals remains unaffecfted due to Frenkel defect (2) In BCC unit cell the void space is 32% (3) Electrical conductivity of semiconductors and metals increases with increase in temperature (4) Density of crystals decreases due to Schottky defect Jee-Main (online)-12

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Sol. (3) Theory Based

Q. In a face centred cubic lattice, atoms of A form the corner points and atoms of B form the face centred points. If two atoms of A are missing from the corner points, the formula of the ionic compound is (1) $\mathrm{AB}_{2}$ ( 2) $\mathrm{AB}_{3}$ (3) $\mathrm{AB}_{4}$ (4) $\mathrm{A}_{2} \mathrm{B}_{5}$ Jee-Main (online)-13

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Sol. (3)

Q. Which one of the following statements about packing in solids is incorrect ? (1) Void space in ccp mode of packing is 26% (2) Coordination number in hcp mode of packing is 12 (3) Void space in hcp mode of packing is 32% (4) Coordination number in bcc mode of packing is 8 Jee-Main (online)-13

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Sol. (3) Theory based

Q. An element having an atomic radius of 0.14 nm crystallizes in an fcc unit cell. What is the length of a side of the cell ? (1) 0.96 nm (2) 0.4 nm (3) 0.24 nm (4) 0.56 nm Jee-Main (online)-13

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Sol. (2)

Q. Expermentally it was found that a metal oxide has formula $\mathrm{M}_{0.98} \mathrm{O}$. Metal M, is present as $\mathrm{M}^{2+}$ and $\mathbf{M}^{3+}$ in its oxide. Fraction of the metal which exists as $\mathrm{M}^{3+}$ would be :- (1) 7.01%          (2) 4.08%           (3) 6.05%           (4) 5.08 Jee-Main (offline)-13

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Sol. (2)

Q. The total number of octahedral void(s) per atom present in a cubic close packed structure is :- (1) 1          (2) 2              (3) 3              (4) 4 Jee-Main (online)-14

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Sol. (1) Theory based

Q. In a monoclinic unit cell, the relation of sides and angles are respectively (1) $\mathrm{a} \neq \mathrm{b} \neq \mathrm{c}$ and $\alpha \neq \beta \neq \gamma \neq 90^{\circ}$ (2) $a \neq b \neq c$ and $\beta=\gamma=90^{\circ} \neq \alpha$ (3) $a=b \neq c$ and $\alpha=\beta=\gamma=90^{\circ}$ (4) $a \neq b \neq c$ and $\alpha=\beta=\gamma=90^{\circ}$ Jee-Main (online)-14

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Sol. (2) Theory based

Q. The appearance of colour in solid alkali metal halides is generally due to : (1) Frenkel defect (2) F-centres (3) Schottky defect (4) Interstitial position Jee-Main (online)-14

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Sol. (2) Theory based

Q. CsCl crystallises in body centred cubic lattice. if ‘a’ is its edge length then which of the following expression is correct : (1) $\mathrm{r}_{\mathrm{Cs}^{+}}+\mathrm{r}_{\mathrm{Cl}^{-}}=\frac{\sqrt{3}}{2} \mathrm{a}$ (2) $\mathrm{r}_{\mathrm{Cs}^{+}}+\mathrm{r}_{\mathrm{Cl}^{-}}=\sqrt{3} \mathrm{a}$ (3) $\quad \mathrm{r}_{\mathrm{Cs}^{+}}+\mathrm{r}_{\mathrm{Cl}^{-}}=3 \mathrm{a}$ (4) $\mathrm{r}_{\mathrm{Cs}^{+}}+\mathrm{r}_{\mathrm{Cl}^{-}}=\frac{3 \mathrm{a}}{2}$ Jee-Main (offline)-14

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Sol. (1)

Q. A metal crystallises in a face centred cubic structure. If the edge length of its unit cell is ‘a’, the closest approach between two atoms in metallic crystal will be :- (1) 2a (2) $2 \sqrt{2} \mathrm{a}$ (3) $\sqrt{2} \mathrm{a}$ (4) $\frac{\mathrm{a}}{\sqrt{2}}$ JEE – Main 2017

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Sol. (4)

Q. Which type of ‘defect’ has the presence of cations in the interstitial sites ? (1) Vacancy defect (2) Frenkel defect (3) Metal deficiency defect (4) Schottky defect JEE – Main 2018

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Sol. (2) In Frenkel defect, some of ion (usually cation due to their small size) missing from their correct position and occupies position in interstitial.

Nuclear Chemistry – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Mains chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas.
Electrochemistry – JEE Main Previous Year Questions with Solutions

Class 9-10, JEE & NEET

JEE Main Previous Year Papers Questions of Chemistry with Solutions are available at eSaral. Practicing JEE Main chapter wise questions of Chemistry will help the JEE aspirants in realizing the question pattern as well as help in analyzing weak & strong areas.   Simulator   Previous Years AIEEE/JEE Mains Questions
Q. Given : $\mathrm{E}_{\mathrm{Fe}^{-3} / \mathrm{Fe}}^{\circ}=-0.036 \mathrm{V}, \quad \mathrm{E}_{\mathrm{Fe}^{-2} / \mathrm{Fe}}^{\circ}=-0.439 \mathrm{V}$. The value of standard electrode potential for the change. $\mathrm{Fe}^{+3}_{(\mathrm{aq})}+\mathrm{e}^{-} \longrightarrow \mathrm{Fe}^{+2}_{(\mathrm{aq})}$ will be :- (1) 0.770 V (2) –0.27 V (3) –0.072 V (4) 0.385 V AIEEE 2009

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Sol. (1) $\mathrm{E}^{\circ}=\frac{3 \times-0.036+2 \times 0.439}{1}=0.77 \Rightarrow \mathrm{A}$

Q. The Gibbs energy for the decomposition of $\mathrm{Al}_{2} \mathrm{O}_{3}$ at $500^{\circ} \mathrm{C}$ is as follows : $\frac{2}{3} \mathrm{Al}_{2} \mathrm{O}_{3} \longrightarrow \frac{4}{3} \mathrm{Al}+\mathrm{O}_{2}, \mathrm{AG}=+966 \mathrm{KJ} \mathrm{mol}^{-1}$ The potential difference needed for electrolytic reduction of $\mathrm{Al}_{2} \mathrm{O}_{3}$ at $500^{\circ} \mathrm{C}$ is at least :- (1) 5.0 V      (2) 4.5 V       (3) 3.0 V         (4) 2.5 V AIEEE 2010

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Sol. (4) $966 \times 10^{3}=4 \times 96500 \times \mathrm{E} \Rightarrow \mathrm{E}=2.5 \mathrm{V}$

Q. Resistance of 0.2 M solution of an electrolyte is $50 \Omega$. The specific conductance of the solution is 1.3 S $\mathrm{m}^{-1}$. If resistance of the 0.4M solution of the same electrolyte is $260 \Omega$, its molar conductivity is :- (1) $6250 \mathrm{Sm}^{2} \mathrm{mol}^{-1}$ (2) $6.25 \times 10^{-4} \mathrm{S} \mathrm{m}^{2} \mathrm{mol}^{-1}$ (3) $625 \times 10^{-4} \mathrm{S} \mathrm{m}^{2} \mathrm{mol}^{-1}$ (4) $62.5 \mathrm{S} \mathrm{m}^{2} \mathrm{mol}^{-1}$ AIEEE 2011/JEE-MAIN 2014

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Sol. (2)

Q. The reduction potential of hydrogen half-cell will be negative if :- (1) $\mathrm{p}\left(\mathrm{H}_{2}\right)=2 \operatorname{atm}\left[\mathrm{H}^{+}\right]=1.0 \mathrm{M}$ (2) $\mathrm{p}\left(\mathrm{H}_{2}\right)=2$ atm and $\left[\mathrm{H}^{+}\right]=2.0 \mathrm{M}$ (3) $\mathrm{p}\left(\mathrm{H}_{2}\right)=1$ atm and $\left[\mathrm{H}^{+}\right]=2.0 \mathrm{M}$ (4) $\mathrm{p}\left(\mathrm{H}_{2}\right)=1$ atm and $\left[\mathrm{H}^{+}\right]=1.0 \mathrm{M}$ AIEEE 2011

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Sol. (1)

Q. The standard reduction potentials for $\mathrm{Zn}^{2+} / \mathrm{Zn}, \mathrm{Ni}^{2+} / \mathrm{Ni}$ and $\mathrm{Fe}^{2+} / \mathrm{Fe}$ are $-0.76,-0.23$ and – 0.44 V respectively. The reaction $\mathrm{X}+\mathrm{Y}^{+2} \rightarrow \mathrm{X}^{2+}+\mathrm{Y}$ will be spontaneous when (1) X = Zn, Y = Ni (2) X = Ni, Y = Fe (3) X = Ni, Y = Zn (4) X = Fe, Y = Zn

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Sol. (1) For spontaneous reaction $\mathrm{E}^{\circ}>0 \mathrm{so}(\mathrm{A})$

Q. Given : Based on the data given above, strongest oxidising agent will be : (1) Cl– (2) $\mathrm{Cr}^{3+}$ (3) $\mathrm{Mn}^{2+}$ (4) $\mathrm{MnO}_{4}^{-}$ JEE-Mains 2013

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Sol. (4) Higher the SRP, stronger will be oxidising agent Hence, $\mathrm{MnO}_{4}^{-}$ is stronger oxidising agent.

Q. The equivalent conductance of NaCl at concentration C and at infinite dilution are $\lambda_{\mathrm{C}}$ and $\lambda_{\infty}$ , respectively. The correct relationship between $\lambda_{\mathrm{C}}$ and $\lambda_{\infty}$ is given as: (1) $\lambda_{\mathrm{C}}=\lambda_{\infty}-(\mathrm{B}) \sqrt{\mathrm{C}}$ (2) $\lambda_{\mathrm{C}}=\lambda_{\infty}+(\mathrm{B}) \sqrt{\mathrm{C}}$ (3) $\lambda_{\mathrm{C}}=\lambda_{\infty}+(\mathrm{B}) \mathrm{C}$ (4) $\lambda_{\mathrm{C}}=\lambda_{\infty}-(\mathrm{B}) \mathrm{C}$ JEE-Mains 2014

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Sol. (1) Fact

Q. At 298 K, the standard reduction potentials are 1.51 V for $\mathrm{MnO}_{4}-| \mathrm{Mn}^{2+}$ , 1.36 V for $\mathrm{Cl}_{2} | \mathrm{Cl}^{-}$, 1.07 V for $\mathrm{Br}_{2} | \mathrm{Br}^{-},$ and $0.54 \mathrm{V}$ for $\mathrm{I}_{2} | \mathrm{I}^{-} .$ At $\mathrm{pH}=3$, permanganate is expected to oxidize $\left(\frac{\mathrm{RT}}{\mathrm{F}}=0.059 \mathrm{V}\right):-$ (1) $\mathrm{Cl}^{-}$ and $\mathrm{Br}^{-}$ (2) $\mathrm{Cl}^{-}, \mathrm{Br}^{-}$ and $\mathrm{I}^{-}$ (3) $\mathrm{Br}^{-}$ and $\mathrm{I}^{-}$ (4) I- only JEE-Mains (online) 2015

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Sol. (3)

Q. A variable, opposite external potential $\left(\mathrm{E}_{\mathrm{ext}}\right)$ is applied to the cell $\mathrm{Zn}\left|\mathrm{Zn}^{2+}(1 \mathrm{M}) \| \mathrm{Cu}^{2+}(1 \mathrm{M})\right| \mathrm{Cu}$, of potential 1.1 V. When $\mathrm{E}_{\mathrm{ext}}<1.1 \mathrm{V}$ and $\mathrm{E}_{\mathrm{ext}}>1.1 \mathrm{V}$ , respectively electrons flow from : (1) anode to cathode in both cases (2) anode to cathode and cathode to anode (3) cathode to anode in both cases (4) cathode to anode and anode to cathode JEE-Mains (online) 2015

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Sol. (2) Fact

Q. Two Faraday of electricity is passed through a solution of $\mathrm{CuSO}_{4}$. The mass of copper deposited at the cathode is : (at. mass of Cu = 63.5 amu) (1) 2g         (2) 127 g          (3) 0 g          (4) 63.5 g JEE-Mains 2015

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Sol. (4) $2 \mathrm{F}=2 \mathrm{eq}=1$ mole $=63.5 \mathrm{gm}$

Q. Galvanization is applying a coating of :- (1)Zn         (2) Pb         (3) Cr        (4) Cu JEE-Mains 2016

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Sol. (1) Galvanization is the process of applying a protective zinc coating of steel or iron, to prevent rusting.

Q. Given (1)Cr (2) $\mathrm{Mn}^{2+}$ (3) $\mathrm{Cr}^{3+}$ (4) $\mathrm{Cl}^{-}$ JEE-Mains 2017

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Sol. (1) Since $\mathrm{Cr}^{+3}$ is having least reducing potential, so Cr is the best Reducing agent.

Q. How long (approximate) should water be electrolysed by passing through 100 amperes current so that the oxygen released can completely burn 27.66 g of diborane ? (Atomic weight of B = 10.8 u) (1)0.8 hours (2) 3.2 hours (3) 1.6 hours (4) 6.4 hours JEE-Mains 2018

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Sol. (2)