At 298 K,
Question: At $298 \mathrm{~K}$, the enthalpy of fusion of a solid $(\mathrm{X})$ is $2.8 \mathrm{~kJ} \mathrm{~mol}^{-1}$ and the enthalpy of vaporisation of the liquid $(\mathrm{X})$ is $98.2 \mathrm{~kJ} \mathrm{~mol}^{-1}$. The enthalpy of sublimation of the substance $(X)$ in $\mathrm{kJ} \mathrm{mol}^{-1}$ is__________ . (in nearest integer) Solution: $\Delta \mathrm{H}_{\text {sub }}=\Delta \mathrm{H}_{\text {fus. }}+\Delta \mathrm{H}_{\text {vap. }}$ $=2.8+98.2$ $=101 \mathrm{~kJ} / \math...
Read More →Consider the cell at
Question: Consider the cell at $25^{\circ} \mathrm{C}$ $\mathrm{Zn}\left|\mathrm{Zn}^{2+}(\mathrm{aq}),(1 \mathrm{M}) \| \mathrm{Fe}^{3+}(\mathrm{aq}), \mathrm{Fe}^{2+}(\mathrm{aq})\right| \mathrm{Pt}(\mathrm{s})$ The fraction of total iron present as $\mathrm{Fe}^{3+}$ ion at the cell potential of $1.500 \mathrm{~V}$ is $\mathrm{x} \times 10^{-2}$. The value of $\mathrm{x}$ is __________ (Nearest integer) $\left(\right.$ Given $\left.: \mathrm{E}_{\mathrm{Fe}^{3+} / \mathrm{Fe}^{2+}}^{0}=0.77 \...
Read More →Prove the following
Question: consider the above reaction, and choose the correct statement:The reaction is not possible in acidic mediumBoth compounds $\mathbf{A}$ and $\mathbf{B}$ are formed equallyCompound $\mathbf{A}$ will be the major productCompound $\mathbf{B}$ will be the major productCorrect Option: 3, Solution:...
Read More →Solve this following
Question: The number of hydrogen bonded water molecule(s) associated with stoichiometry $\mathrm{CuSO}_{4} .5 \mathrm{H}_{2} \mathrm{O}$ is Solution: One hydrogen bonded $\mathrm{H}_{2} \mathrm{O}$ molecule...
Read More →Compound $mathrm{A}$ is converted to B on reaction
Question: Compound $\mathrm{A}$ is converted to $\mathrm{B}$ on reaction with $\mathrm{CHCl}_{3}$ and $\mathrm{KOH}$. The compound $\mathrm{B}$ is toxic and can be decomposed by C. A, B and C respectively are :primary amine, nitrile compound, conc. $\mathrm{HCl}$secondary amine, isonitrile compound, conc. $\mathrm{NaOH}$primary amine, isonitrile compound, conc. $\mathrm{HCl}$secondary amine, nitrile compound, conc. $\mathrm{NaOH}$Correct Option: , 3 Solution:...
Read More →For the reaction
Question: For the reaction $\mathrm{A}+\mathrm{B} \rightleftharpoons 2 \mathrm{C}$ the value of equilibrium constant is 100 at $298 \mathrm{~K}$. If the initial concentration of all the three species is $1 \mathrm{M}$ each, then the equilibrium concentration of $\mathrm{C}$ is $x \times 10^{-1}$ M. The value of $x$ is______ (Nearest integer) Solution: $\mathrm{K}=\frac{[\mathrm{C}]_{\mathrm{eq}}^{2}}{[\mathrm{~A}]_{\mathrm{eq}}[\mathrm{B}]_{\mathrm{eq}}}=\frac{(1+2 \mathrm{x})^{2}}{(1-\mathrm{x}...
Read More →For a first order reaction, the ratio of the time for
Question: For a first order reaction, the ratio of the time for $75 \%$ completion of a reaction to the time for $50 \%$ completion is (Integer answer) Solution: $k=\frac{2.303}{t} \log \frac{a}{a-x}$ $\frac{2.303}{t_{50 \%}} \log \frac{100}{100-50}=\frac{2.303}{t_{75 \%}} \log \frac{100}{100-75}$ $\mathrm{t}_{75 \%}=2 \mathrm{t}_{50 \%}$...
Read More →Solve the following
Question: Consider the above reaction and identify "Y"$-\mathrm{CH}_{2} \mathrm{NH}_{2}$$-\mathrm{CONH}_{2}$$-\mathrm{CHO}$$-\mathrm{COOH}$Correct Option: , 3 Solution:...
Read More →The addition of dilute NaOH to Cr3+ salt solution will give :
Question: The addition of dilute NaOH to Cr3+ salt solution will give :a solution of $\left[\mathrm{Cr}(\mathrm{OH})_{4}\right]^{-}$precipitate of $\mathrm{Cr}_{2} \mathrm{O}_{3}\left(\mathrm{H}_{2} \mathrm{O}\right)$precipitate of $\left[\mathrm{Cr}(\mathrm{OH})_{6}\right]^{3-}$precipitate of $\mathrm{Cr}(\mathrm{OH})_{3}$Correct Option: , 2 Solution: $\mathrm{Cr}^{3+}+\underset{\text { dil. }}{\mathrm{NaOH}} \longrightarrow \underset{\text { precipitate }}{\mathrm{Cr}_{2} \mathrm{O}_{3} \cdot\...
Read More →Solve this
Question: $\mathrm{CO}_{2}$ gas is bubbled through water during a soft drink manufacturing process at $298 \mathrm{~K}$. If $\mathrm{CO}_{2}$ exerts a partial pressure of $0.835$ bar then $\mathrm{x} \mathrm{m} \mathrm{mol}$ of $\mathrm{CO}_{2}$ would dissolve in $0.9 \mathrm{~L}$ of water. The value of $x$ is - (Nearest integer) (Henry's law constant for $\mathrm{CO}_{2}$ at $298 \mathrm{~K}$ is $1.67 \times 10^{3}$ bar $)$ Solution: From Henry's law $\mathrm{P}_{\mathrm{gas}}=\mathrm{K}_{\math...
Read More →The number of halogen/(s) forming halic (V) acid is
Question: The number of halogen/(s) forming halic (V) acid is Solution: The number of halogen forming halic (V) acid $\mathrm{HClO}_{3}$ $\mathrm{HBrO}_{3}$ $\mathrm{HIO}_{3}$ So Answer is 3...
Read More →A source of monochromatic radiation
Question: A source of monochromatic radiation of wavelength $400 \mathrm{~nm}$ provides $1000 \mathrm{~J}$ of energy in 10 seconds. When this radiation falls on the surface of sodium, $x \times 10^{20}$ electrons are ejected per second. Assume that wavelength $400 \mathrm{~nm}$ is sufficient for ejection of electron from the surface of sodium metal. The value of $x$ is________ (Nearest integer) $\left(\mathrm{h}=6.626 \times 10^{-34} \mathrm{Js}\right)$ Solution: Total energy provided by Source ...
Read More →Choose the correct statement from the following :
Question: Choose the correct statement from the following :The standard enthalpy of formation for alkali metal bromides becomes less negative on descending the group.The low solubility of CsI in water is due to its high lattice enthalpy.Among the alkali metal halides, LiF is least soluble in water.LiF has least negative standard enthalpy of formation among alkali metal fluorides.Correct Option: , 3 Solution: 1. Standard enthalpy of formation for alkali metal bromides becomes more negative on des...
Read More →The total number of reagents from those given below, that can convert nitrobenzene into aniline is - (Integer answer)
Question: The total number of reagents from those given below, that can convert nitrobenzene into aniline is - (Integer answer) I. $\mathrm{Sn}-\mathrm{HCl}$ II. $\mathrm{Sn}-\mathrm{NH}_{4} \mathrm{OH}$ III. $\mathrm{Fe}-\mathrm{HCl}$ IV.Zn - HCl V. $\mathrm{H}_{2}-\mathrm{Pd}$ VI. $\mathrm{H}_{2}$ - Raney Nickel Solution: (i) $\mathrm{Sn}+\mathrm{HCl}$ (ii) $\mathrm{Fe}+\mathrm{HCl}$ (iii) $\mathrm{Zn}+\mathrm{HCl}$ (iv) $\mathrm{H}_{2}-\mathrm{Pd}$ (v) $\mathrm{H}_{2}$ (Raney $\mathrm{Ni}$ )...
Read More →Compound A gives D-Galactose and D-Glucose on hydrolysis.
Question: Compound A gives D-Galactose and D-Glucose on hydrolysis. The compound $\mathbf{A}$ is :AmyloseSucroseMaltoseLactoseCorrect Option: , 4 Solution: Lactose : It is a disaccharide of $\beta$-D-Galactose and $\beta-\mathrm{D}-\mathrm{Glucose}$ with $\mathrm{C}_{1}$ of galactose and $\mathrm{C}_{4}$ of glucose link. Lactose : $\beta-\mathrm{D}-$ Galactose $+\beta-\mathrm{D}-$ Glucose...
Read More →Three moles of
Question: Three moles of $\mathrm{AgCl}$ get precipitated when one mole of an octahedral co-ordination compound with empirical formula $\mathrm{CrCl}_{3} .3 \mathrm{NH}_{3} .3 \mathrm{H}_{2} \mathrm{O}$ reacts with excess of silver nitrate. The number of chloride ions satisfying the secondary valency of the metal ion is Solution: Mole of $\mathrm{AgCl}$ precipitated is equal the mole of $\mathrm{Cl}^{-}$ present in ionization sphere. $\left[\mathrm{Cr}\left(\mathrm{H}_{2} \mathrm{O}\right)_{3}\l...
Read More →The metal that can be purified economically
Question: The metal that can be purified economically by fractional distillation method is:$\mathrm{Fe}$$\mathrm{Zn}$$\mathrm{Cu}$$\mathrm{Ni}$Correct Option: 2, Solution: Zinc can be purified economically by fractional distillation....
Read More →Solve this following
Question: Consider the sulphides $\mathrm{HgS}, \mathrm{PbS}, \mathrm{CuS}, \mathrm{Sb}_{2} \mathrm{~S}_{3}$, $\mathrm{As}_{2} \mathrm{~S}_{3}$ and $\mathrm{CdS}$. Number of these sulphides soluble in $50 \% \mathrm{HNO}_{3}$ is Solution: $\mathrm{Pbs}, \mathrm{CuS}, \mathrm{As}_{2} \mathrm{~S}_{3}, \mathrm{CdS}$ are soluble in $50 \% \mathrm{HNO}_{3}$ $\mathrm{HgS}, \mathrm{Sb}_{2} \mathrm{~S}_{3}$ are insoluble in $50 \% \mathrm{HNO}_{3}$ So Answer is 4 ....
Read More →The molarity of the solution prepared by dissolving
Question: The molarity of the solution prepared by dissolving $6.3 \mathrm{~g}$ of oxalic acid $\left(\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4} .2 \mathrm{H}_{2} \mathrm{O}\right)$ in $250 \mathrm{~mL}$ of water in mol $\mathrm{L}^{-1}$ is $\mathrm{x} \times 10^{-2}$. The value of $\mathrm{x}$ is (Nearest integer) [Atomic mass : $\mathrm{H}: 1.0, \mathrm{C}: 12.0, \mathrm{O}: 16.0]$ Solution: $\left[\mathrm{H}_{2} \mathrm{C}_{2} \mathrm{O}_{4} \cdot 2 \mathrm{H}_{2} \mathrm{O}\right]=\frac{\t...
Read More →In the given reaction 3-Bromo-2, 2-dimethyl
Question: In the given reaction 3-Bromo-2, 2-dimethyl butane $\stackrel{\mathrm{C}_{2} \mathrm{H}_{5} \mathrm{OH}}{\longrightarrow} \underset{\text { (Major Product) }}{\text { 'A }^{\prime}}$ Product $\mathrm{A}$ is:2-Ethoxy-3, 3-dimethyl butane1-Ethoxy-3, 3-dimethyl butane2-Ethoxy-2, 3-dimethyl butane2 -Hydroxy-3, 3-dimethyl butaneCorrect Option: , 3 Solution:...
Read More →An organic compound
Question: An organic compound ' $\mathrm{A}^{\prime} \mathrm{C}_{4} \mathrm{H}_{8}$ on treatment with $\mathrm{KMnO}_{4} / \mathrm{H}^{+}$yields compound ' $\mathrm{B}$ ' $\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}$. Compound 'A' also yields compound 'B' an ozonolysis. Compound 'A' is :2-Methylpropene1-MethylcyclopropaneBut-2-eneCyclobutaneCorrect Option: 1 Solution:...
Read More →Given below are two statements :
Question: Given below are two statements : Statement I : Penicillin is a bacteriostatic type antibiotic. Statement II : The general structure of Penicillin is: Choose the correct option :Both statement I and statement II are falseStatement I is incorrect but statement II is trueBoth statement I and statement II are trueStatement I is correct but statement II is falseCorrect Option: , 2 Solution: Statement I : Pencillin is bactericidal not bacteriostatic hence given statement is false. Statement ...
Read More →Consider the following cell reaction :
Question: Consider the following cell reaction : $\mathrm{Cd}_{(s)}+\mathrm{Hg}_{2} \mathrm{SO}_{4(s)}+\frac{9}{5} \mathrm{H}_{2} \mathrm{O}_{(l)} \rightleftharpoons \mathrm{CdSO}_{4} \cdot \frac{9}{5} \mathrm{H}_{2} \mathrm{O}_{(s)}+2 \mathrm{Hg}_{(l)}$ The value of $\mathrm{E}_{\text {cell }}^{0}$ is $4.315 \mathrm{~V}$ at $25^{\circ} \mathrm{C}$. If $\Delta \mathrm{H}^{\circ}=-825.2 \mathrm{~kJ} \mathrm{~mol}^{-1}$, the standard entropy change $\Delta \mathrm{S}^{\circ}$ in $\mathrm{J} \mathr...
Read More →In the leaching of alumina from bauxite,
Question: In the leaching of alumina from bauxite, the ore expected to leach out in the process by reacting with $\mathrm{NaOH}$ is :$\mathrm{TiO}_{2}$$\mathrm{Fe}_{2} \mathrm{O}_{3}$$\mathrm{ZnO}$$\mathrm{SiO}_{2}$Correct Option: , 4 Solution: In bauxite impurities of $\mathrm{Fe}_{2} \mathrm{O}_{3}, \mathrm{TiO}_{2}$ and $\mathrm{SiO}_{2}$ are present, $\mathrm{Fe}_{2} \mathrm{O}_{3}$ and $\mathrm{TiO}_{2}$ are basic oxides therefore does not reacts with or dissolve in $\mathrm{NaOH}$ whereas ...
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