Chemical & Ionic Equilibrium · JEE Main previous year questions

2022 34 questions

1. Q862022 · 27 Jun 2022 · Shift 2· Numerical answer

   For the reaction taking place in the cell : $\text{Pt (s)}|{\text{H}}_2\text{ (g)}|{\text{H}}^{+}\text{(aq)}\parallel {\text{Ag}}^{+}\text{(aq)}|\text{Ag (s)}$ $E_{cell}^{\circ }=+0.5332\text{ V}$. The value of ${\Delta }_f{G}^{\circ }$ is ________ ${\text{kJ mol}}^{-1}$. (in nearest integer)

   Show answer

   Answer: 51 or 103

2. Q822022 · 26 Jun 2022 · Shift 1· Numerical answer

   A 0.5 percent solution of potassium chloride was found to freeze at $-0.24^{\circ }\text{C}$. The percentage dissociation of potassium chloride is ________. (Nearest integer) (Molal depression constant for water is $1.80{\text{ K kg mol}}^{-1}$ and molar mass of KCl is $74.6{\text{ g mol}}^{-1}$)

   Show answer

   Answer: 98

3. Q832022 · 26 Jun 2022 · Shift 1· Numerical answer

   50 mL of 0.1 M $\mathrm{C}{\mathrm{H}}_3\mathrm{COOH}$ is being titrated against 0.1 M NaOH. When 25 mL of NaOH has been added, the pH of the solution will be ________ $\times 10^{-2}$. (Nearest integer) (Given : $\mathrm{p}{\mathrm{K}}_{\mathrm{a}}(\mathrm{C}{\mathrm{H}}_3\mathrm{COOH})=4.76$) $\log 2=0.30$ $\log 3=0.48$ $\log 5=0.69$ $\log 7=0.84$ $\log 11=1.04$

   Show answer

   Answer: 476

4. Q852022 · 26 Jun 2022 · Shift 2· Numerical answer

   $40\%$ of $\mathrm{HI}$ undergoes decomposition to ${\mathrm{H}}_2$ and ${\mathrm{I}}_2$ at $300\mathrm{K}$. $\Delta {\mathrm{G}}^{\ominus }$ for this decomposition reaction at one atmosphere pressure is ____ $\mathrm{J}\mathrm{mo}{\mathrm{l}}^{-1}$. [nearest integer] (Use $\mathrm{R}=8.31\mathrm{J}{\mathrm{K}}^{-1}\mathrm{mo}{\mathrm{l}}^{-1}$ ; $\log 2=0.3010$, $\ln 10=2.3$, $\log 3=0.477$)

   Show answer

   Answer: 2735

5. Q632022 · 25 Jun 2022 · Shift 1

   Number of electron deficient molecules among the following ${\mathrm{PH}}_3$, ${\mathrm{B}}_2{\mathrm{H}}_6$, ${\mathrm{CCl}}_4$, ${\mathrm{NH}}_3$, $\mathrm{LiH}$ and ${\mathrm{BCl}}_3$ is

   1. A.$0$
   2. B.$1$
   3. C.$2$
   4. D.$3$
   Show answer

   Answer: C

6. Q852022 · 25 Jun 2022 · Shift 1· Numerical answer

   The standard free energy change ($\Delta {\mathrm{G}}^{\circ }$) for $50\%$ dissociation of ${\mathrm{N}}_2{\mathrm{O}}_4$ into ${\mathrm{NO}}_2$ at $27^{\circ }\text{C}$ and $1\text{ atm}$ pressure is $-x{\text{ J mol}}^{-1}$. The value of $x$ is $\underline{}$. (Nearest Integer) [Given : $\mathrm{R}=8.31{\text{ J K}}^{-1}{\text{ mol}}^{-1}$, $\log 1.33=0.1239$, $\ln 10=2.3$]

   Show answer

   Answer: 710

7. Q642022 · 25 Jun 2022 · Shift 2

   The ${\mathrm{K}}_{\mathrm{sp}}$ for bismuth sulphide $(\mathrm{B}{\mathrm{i}}_2{\mathrm{S}}_3)$ is $1.08\times 10^{-73}$. The solubility of $\mathrm{B}{\mathrm{i}}_2{\mathrm{S}}_3$ in $\mathrm{mol}{\mathrm{L}}^{-1}$ at $298\mathrm{K}$ is :

   1. A.$1.0\times 10^{-15}$
   2. B.$2.7\times 10^{-12}$
   3. C.$3.2\times 10^{-10}$
   4. D.$4.2\times 10^{-8}$
   Show answer

   Answer: A

8. Q662022 · 25 Jun 2022 · Shift 2

   Given below are two statements one is labelled as Assertion A and the other is labelled as Reason R : Assertion A : The amphoteric nature of water is explained by using Lewis acid/base concept. Reason R : Water acts as an acid with $\mathrm{N}{\mathrm{H}}_3$ and as a base with ${\mathrm{H}}_2\mathrm{S}$. In the light of the above statements choose the correct answer from the options given below :

   1. A.Both A and R are true and R is the correct explanation of A.
   2. B.Both A and R are true but R is NOT the correct explanation of A.
   3. C.A is true but R is false.
   4. D.A is false but R is true.
   Show answer

   Answer: D

9. Q822022 · 24 Jun 2022 · Shift 2· Numerical answer

   ${\mathrm{PCl}}_5$ dissociates as ${\mathrm{PCl}}_5(\mathrm{g})\rightleftharpoons {\mathrm{PCl}}_3(\mathrm{g})+{\mathrm{Cl}}_2(\mathrm{g})$ $5\text{ moles}$ of ${\mathrm{PCl}}_5$ are placed in a $200\text{ litre}$ vessel which contains $2\text{ moles}$ of ${\mathrm{N}}_2$ and is maintained at $600\text{ K}$. The equilibrium pressure is $2.46\text{ atm}$. The equilibrium constant ${\mathrm{K}}_{\mathrm{p}}$ for the dissociation of ${\mathrm{PCl}}_5$ is $\underline{}\times 10^{-3}$. (nearest integer) (Given : $\mathrm{R}=0.082{\text{ L atm K}}^{-1}{\text{ mol}}^{-1}$; Assume ideal gas behaviour)

   Show answer

   Answer: 1107