When H₂S is passed through an aqueous solution of an equimolar mixture of Zn²⁺ and Pb²⁺ acidified with dilute acetic acid, ZnS is not precipitated, because

1. ${\mathrm{K}}_{\mathrm{sp}} \left(\mathrm{ZnS}\right)<{\mathrm{K}}_{\mathrm{sp}} \left(\mathrm{PbS}\right)$

2. ${\mathrm{K}}_{\mathrm{sp}} \left(\mathrm{ZnS}\right)>{\mathrm{K}}_{\mathrm{sp}} \left(\mathrm{PbS}\right)$

3. ${\mathrm{H}}_2\mathrm{S} \mathrm{decreases} \mathrm{the} {\mathrm{K}}_{\mathrm{sp} }\mathrm{of} \mathrm{Zns}$

4. ${\mathrm{H}}_2\mathrm{S} \mathrm{increases} \mathrm{the} {\mathrm{K}}_{\mathrm{sp}} \mathrm{of} \mathrm{PbS}$

When 0.1 mol of CH₃NH₂ $({\mathrm{K}}_{\mathrm{b}}=5\times {10}^{-4})$ is mixed with 0.08 mol of HCl and diluted to 1 L, the H⁺ ion concentration in the solution will be :

1. $8\times {10}^{-11}$ $\mathrm{M}$

2. $6\times {10}^{-5}$ $\mathrm{M}$

3. $1.6\times {10}^{-11}$ $\mathrm{M}$

4. $8\times {10}^{-2}$ $\mathrm{M}$

The concentration of hydroxyl ion in a solution left after mixing 100 mL of 0.1 M MgCl₂ and 100 mL of 0.2 M NaOH $[{\mathrm{K}}_{\mathrm{sp}} \mathrm{of} \mathrm{Mg}{\left(\mathrm{OH}\right)}_2=1.2\times {10}^{-11}]$ is

1. $2.8\times {10}^{-3}$

2. $2.8\times {10}^{-2}$

3. $2.8\times {10}^{-4}$

4. $2.8\times {10}^{-5}$

The hydolysis of the salt of strong acid and weak base is called:

(1) anionic hydrolysis

(2) cationic hydrolysis

(3) amphoteric hydrolysis

(4) none of the above

When 10 ml of 0.1 M acetic acid (pK_a=5.0) is titrated against 10 ml of 0.1 M
ammonia solution (pK_b=5.0), the pH at equivalence point will be:

Assuming no change in volume, calculate the minimum mass of NaCl (approx.) necessary to dissolve 0.01 mol AgCl in 100 L solution.

[Given $K_{sp}\left(AgCl\right)={10}^{-10}; K_f\left(AgC{l}_2^{-}\right)=3\times {10}^5]$

1. 15 kg

2. 21 kg

3. 10 kg

4. 19kg

A 0.1 molar solution of weak base BOH is 1% dissociated. If 0.2 moles of BCl is added in 1 litre solution of BOH, the degree of dissociation of BOH will become

1. $2\times {10}^{-3}$

2. $5\times {10}^{-5}$

3. 0.05

4. 0.02

The exact concentration of $H^{+}$ ion in ${10}^{-3}$ M aq. HCl solution at $25°C$ is:

1. ${10}^{-3}$

2. ${10}^{-3}+{10}^{-7}$

3. ${10}^{-3}+\frac{Kw}{\left[H^{+}\right]}$

4. ${10}^{-3}+\frac{Kw}{\left[O{H}^{-}\right]}$

A weak base BOH with $K_{b }={10}^{-5}$ is titrated with a strong acid HCl. At $\frac{3}{4}th$ of the equivalence point pH of solution is

(1) 5+log3

(2) 5-log3

(3) 9.425

(4) 8.523

Ammonia at a pressure 10 atm and $C{O}_2$ at a pressure at 20 atm are introduced into an evacuated chamber. If $K_p$ for the reaction

$N{H}_{2}COON{H}_4\left(s\right) \rightleftharpoons 2N{H}_3\left(g\right)+C{O}_2\left(g\right)$ is 2020 $at{m}^2$ at 400K then the final pressure in the chamber would be

(1) Less than 30 atm

(2) More than 30 atm

(3) Equal to 30 atm

(4) Unpredictable