The correct pair(s) of the ambident nucleophiles is (are):
Question: The correct pair(s) of the ambident nucleophiles is (are): (A) $\mathrm{AgCN} / \mathrm{KCN}$ (B) RCOOAg/RCOOK (C) $\mathrm{AgNO}_{2} / \mathrm{KNO}_{2}$ (D) $\mathrm{AgI} / \mathrm{KI}$ (B) and $(C)$ only(A) only(A) and $(C)$ only(B) onlyCorrect Option: , 3 Solution: Ambident nucleophile (A) $\mathrm{KCN} \ \mathrm{AgCN}$ (C) $\mathrm{AgNO}_{2} \ \mathrm{KNO}_{2}$...
Read More →The polymer formed on heating Novolac
Question: The polymer formed on heating Novolac with formaldehyde is :BakelitePolyesterMelamineNylon 6,6Correct Option: 1 Solution: Novolac $+$ formaldehyde $\rightarrow$ Bakelite...
Read More →The decomposition of formic acid on gold surface follows first order kinetics
Question: The decomposition of formic acid on gold surface follows first order kinetics constant at $300 \mathrm{~K}$ is $1.0 \times 10^{-3} \mathrm{~s}^{-1}$ and the activation energy $\mathrm{E}_{\mathrm{a}}=11.488 \mathrm{~kJ} \mathrm{~mol}^{-1}$, the rate constant at $200 \mathrm{~K}$ is_________ $\times 10^{-5} \mathrm{~s}^{-1}$. (Round of to the Nearest Integer). (Given : $\mathrm{R}=8.314 \mathrm{~J} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$ ) Solution: $\mathrm{K}_{300}=10^{-4} \quad \mathrm{...
Read More →Match List-I and List-II :
Question: Match List-I and List-II :. Choose the correct answer from the options given below: $(\mathrm{a})-(\mathrm{ii}),(\mathrm{b})-(\mathrm{iii}),(\mathrm{c})-(\mathrm{i}),(\mathrm{d})-(\mathrm{iv})$(a)-(iv), (b)-(i), (c)-(ii), (d)-(iii)(a)-(i), (b)-(iii), (c)-(ii), (d)-(iv)(a)-(ii), (b)-(i), (c)-(iv), (d)-(iii)Correct Option: , 4 Solution:...
Read More →For the reaction
Question: For the reaction $\mathrm{C}_{2} \mathrm{H}_{6} \rightarrow \mathrm{C}_{2} \mathrm{H}_{4}+\mathrm{H}_{2}$ the reaction enthalpy $\Delta_{\mathrm{r}} \mathrm{H}=$ $\mathrm{kJ} \mathrm{mol}^{-1}$ (Round off to the Nearest Integer). [Given : Bond enthalpies in $\mathrm{kJ} \mathrm{mol}^{-1}: \mathrm{C}-\mathrm{C}$ : $347, \mathrm{C}=\mathrm{C}: 611 ; \mathrm{C}-\mathrm{H}: 414, \mathrm{H}-\mathrm{H}: 436]$ Solution: $\Delta_{\mathrm{r}} \mathrm{H}=\left[\in_{\mathrm{C}-\mathrm{C}}+2 \in_{...
Read More →The functional groups that are responsible for the ion-exchange property of cation and anion exchange resins, respectively, are :
Question: The functional groups that are responsible for the ion-exchange property of cation and anion exchange resins, respectively, are :$-\mathrm{SO}_{3} \mathrm{H}$ and $-\mathrm{NH}_{2}$$-\mathrm{SO}_{3} \mathrm{H}$ and $-\mathrm{COOH}$$-\mathrm{NH}_{2}$ and $-\mathrm{COOH}$$-\mathrm{NH}_{2}$ and $-\mathrm{SO}_{3} \mathrm{H}$Correct Option: 1 Solution: Cation exchanger contains $-\mathrm{SO}_{3} \mathrm{H}$ or $-\mathrm{COOH}$ groups while anion exchanger contains basic groups like $-\mathr...
Read More →The major product formed in the following
Question: The major product formed in the following reaction is : Correct Option: 1 Solution:...
Read More →A certain element crystallises in a bcc lattice of unit cell edge length 27 Å.
Question: A certain element crystallises in a bcc lattice of unit cell edge length 27 Å. If the same element under the same conditions crystallises in the fcc lattice, the edge length of the unit cell in Å will be ________. (Round off to the Nearest Integer). [Assume each lattice point has a single atom] [Assume $\sqrt{3}=1.73, \sqrt{2}=1.41$ ] Solution: For $\mathrm{BCC} \sqrt{3} \mathrm{a}=4 \mathrm{r}$ so $\quad r=\frac{\sqrt{3}}{4} \times 27$ for $\mathrm{FCC} \quad \mathrm{a}=2 \sqrt{2} \ma...
Read More →The set of elements that differ in mutual relationship from those of the other sets is :
Question: The set of elements that differ in mutual relationship from those of the other sets is : $\mathrm{Li}-\mathrm{Mg}$$\mathrm{B}-\mathrm{Si}$$\mathrm{Be}-\mathrm{Al}$$\mathrm{Li}-\mathrm{Na}$Correct Option: , 4 Solution: $\mathrm{Li}-\mathrm{Mg}, \mathrm{B}-\mathrm{Si}, \mathrm{Be}-\mathrm{Al}$ show diagonal relationship but $\mathrm{Li}$ and $\mathrm{Na}$ do not show diagonal relationship as both belongs to same group and not placed diagonally....
Read More →2 NO(g) + Cl2(g) ⇌ 2 NOCl (s) This reaction was studied at
Question: $2 \mathrm{NO}(\mathrm{g})+\mathrm{Cl}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{NOCl}(\mathrm{s})$ This reaction was studied at $-10^{\circ} \mathrm{C}$ and the following data was obtained $[\mathrm{NO}]_{0}$ and $\left[\mathrm{Cl}_{2}\right]_{0}$ are the initial concentrations and $\mathrm{r}_{0}$ is the initial reaction rate. The overall order of the reaction is______. (Round off to the Nearest Integer). Solution: $\mathrm{r}=\mathrm{k}[\mathrm{NO}]^{\mathrm{m}}\left[\mathrm{Cl}...
Read More →The major product formed in the following
Question: The major product formed in the following reaction is : Correct Option: , 3 Solution:...
Read More →Fructose is an example of :-
Question: Fructose is an example of :-PyranoseKetohexoseAldohexoseHeptoseCorrect Option: , 2 Solution: Fructose is a ketohexose....
Read More →The major product formed in the following
Question: The major product formed in the following reaction is : Correct Option: , 3 Solution:...
Read More →Two salts A2X and MX have the same value o
Question: Two salts $\mathrm{A}_{2} \mathrm{X}$ and $\mathrm{MX}$ have the same value of solubility product of $4.0 \times 10^{-12}$. The ratio of their molar solubilities i.e. $\frac{\mathrm{S}\left(\mathrm{A}_{2} \mathrm{X}\right)}{\mathrm{S}(\mathrm{MX})}=$_________ (Round off to the Nearest Integer). Solution: For $\mathrm{A}_{2} \mathrm{X}$ $\mathrm{A}_{2} \mathrm{X} \rightarrow 2 \mathrm{~A}^{+}+\mathrm{X}^{2-}$ $2 \mathrm{~S}_{1} \quad \mathrm{~S}_{1}$ $\mathrm{K}_{\mathrm{sp}}=4 \mathrm{...
Read More →The major products formed in the following reaction sequence
Question: The major products formed in the following reaction sequence $\mathbf{A}$ and $\mathbf{B}$ are : Correct Option: 1 Solution:...
Read More →In order to prepare a buffer solution of pH 5.74,
Question: In order to prepare a buffer solution of pH 5.74, sodium acetate is added to acetic acid. If the concentration of acetic acid in the buffer is $1.0$ M, the concentration of sodium acetate in the buffer is_________M. (Round off to the Nearest Integer). [Given : $\mathrm{pKa}$ (acetic acid) $=4.74]$ Solution: $\mathrm{pH}=\mathrm{pKa}+\log \frac{[\mathrm{CB}]}{[\mathrm{WA}]}$ $5.74=4.74+\log \frac{[\mathrm{CB}]}{1}$ $\Rightarrow[\mathrm{CB}]=10 \mathrm{M}$...
Read More →AX is a covalent diatomic molecule
Question: $\mathrm{AX}$ is a covalent diatomic molecule where $\mathrm{A}$ and $X$ are second row elements of periodic table. Based on Molecular orbital theory, the bond order of $A X$ is 25 . The total number of electrons in $\mathrm{AX}$ is_________ (Round off to the Nearest Integer). Solution: AX is a covalent diatomic molecule. The molecule is NO. Total no. of electrons is 15 ....
Read More →The chemical that is added to reduce the melting
Question: The chemical that is added to reduce the melting point of the reaction mixture during the extraction of aluminium is:CryoliteBauxiteCalamineKaoliteCorrect Option: 1 Solution: To reduce the melting point of reaction mixture, cryolite is added....
Read More →When light of wavelength 248 nm falls on a metal of threshold energy 3.0 eV,
Question: When light of wavelength $248 \mathrm{~nm}$ falls on a metal of threshold energy $3.0 \mathrm{eV}$, the de-Broglie wavelength of emitted electrons is______________A. (Round off to the Nearest Integer). $\left[\right.$ Use $: \sqrt{3}=1.73, \mathrm{~h}=6.63 \times 10^{-34} \mathrm{Js}$ $\mathrm{m}_{\mathrm{e}}=9.1 \times 10^{-31} \mathrm{~kg} ; \mathrm{c}=3.0 \times 10^{8} \mathrm{~ms}^{-1}$ $\left.1 \mathrm{eV}=1.6 \times 10^{-19} \mathrm{~J}\right]$ Solution: Energy incident $=\frac{h...
Read More →Which one of the following when dissolved in water gives
Question: Which one of the following when dissolved in water gives coloured solution in nitrogen atmosphere?$\mathrm{CuCl}_{2}$$\mathrm{AgCl}$$\mathrm{ZnCl}_{2}$$\mathrm{Cu}_{2} \mathrm{Cl}_{2}$Correct Option: 1, Solution:...
Read More →In a binary compound,
Question: In a binary compound, atoms of element $\mathrm{A}$ form a hcp structure and those of element $\mathrm{M}$ occupy $2 / 3$ of the tetrahedral voids of the hcp structure. The formula of the binary compound is :$\mathrm{M}_{2} \mathrm{~A}_{3}$$\mathrm{M}_{4} \mathrm{~A}_{3}$$\mathrm{M}_{4} \mathrm{~A}$$\mathrm{MA}_{3}$Correct Option: , 2 Solution: $\mathbf{M}_{12 \times \frac{2}{3}} \mathrm{~A}_{6}$ $\mathrm{M}_{8} \mathrm{~A}_{6}$ $\mathrm{M}_{4} \mathrm{~A}_{3}$...
Read More →The number of ionisable hydrogens present in the product
Question: The number of ionisable hydrogens present in the product obtained from a reaction of phosphorus trichloride and phosphonic acid is:3021Correct Option: , 3 Solution: $\mathrm{PCl}_{3}+\mathrm{H}_{3} \mathrm{PO}_{3} \rightarrow \mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{5}$...
Read More →Which one of the following is correct for the adsorption
Question: Which one of the following is correct for the adsorption of a gas at a given temperature on a solid surface?$\Delta \mathrm{H}0, \Delta \mathrm{S}0$$\Delta \mathrm{H}0, \Delta \mathrm{S}0$$\Delta \mathrm{H}0, \Delta \mathrm{S}0$$\Delta \mathrm{H}0, \Delta \mathrm{S}0$Correct Option: , 3 Solution: (i) Adsorption of gas at metal surface is an exothermic process so $\Delta \mathrm{H}0$ (ii) As the adsorption of gas on metal surface reduces the free movement of gas molecules thus restricti...
Read More →A 6.50 molal solution of KOH (aq.) has a density
Question: A $6.50$ molal solution of $\mathrm{KOH}$ (aq.) has a density of $1.89 \mathrm{~g} \mathrm{~cm}^{-3}$. The molarity of the solution is___________ $\mathrm{mol} \mathrm{dm}^{-3}$. (Round off to the Nearest Integer). [Atomic masses: $\mathrm{K}: 39.0 \mathrm{u} ; \mathrm{O}: 16.0 \mathrm{u} ; \mathrm{H}: 1.0 \mathrm{u}$ ] Solution: $6.5$ molal $\mathrm{KOH}=1000 \mathrm{gm}$ solvent has $6.5$ moles $\mathrm{KOH}$ so $\mathrm{wt}$ of solute $=6.5 \times 56$ $=364 \mathrm{gm}$ wt of soluti...
Read More →Given below are two statements : One is labelled as Assertion A and the other
Question: Given below are two statements : One is labelled as Assertion A and the other labelled as reason $\mathrm{R}$ Assertion A : During the boiling of water having temporary hardness, $\mathrm{Mg}\left(\mathrm{HCO}_{3}\right)_{2}$ is converted to $\mathrm{MgCO}_{3}$. Reason $\mathbf{R}$ : The solubility product of $\mathrm{Mg}(\mathrm{OH})_{2}$ is greater than that of $\mathrm{MgCO}_{3}$. In the light of the above statements, choose the most appropriate answer from the options given below :...
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