If solubility product of Ca${\left(\mathrm{OH}\right)}_2<mspace\; width="1em"></mspace>\mathrm{is}<mspace\; width="1em"></mspace>{10}^{-11}$, the pH at which $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ precipitate from a solution containing decimolar concentration of ${\mathrm{Ca}}^{2+}$ is
Which of the following pH conditions is required for Ca(OH)₂ to start precipitating from a 0.1 M Ca²⁺ solution given that its solubility product is 10⁻¹¹?

1. pH <5

2. 9<pH<5

3. pH>9

4. 7<pH>9

For the reaction,

${\mathrm{CuSO}}_4.5{\mathrm{H}}_2\mathrm{O}\left(\mathrm{s}\right)\rightleftharpoons {\mathrm{CuSO}}_4.3{\mathrm{H}}_2\mathrm{O}\left(\mathrm{s}\right)+2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{g}\right)$

choose the correct representation:

1. ${\mathrm{K}}_{\mathrm{P}}={\mathrm{P}}_{{\mathrm{H}}_2\mathrm{O}}^2$

2. K_c = [H₂O]²

3. ${\mathrm{K}}_{\mathrm{P}}={\mathrm{K}}_{\mathrm{C}}{\left(\mathrm{RT}\right)}^2$

4. All of the above

The solubility of PbCI₂  in water is  0.01 M  at  25 °C. The maximum concentration of Pb²⁺ in 0.1 M NaCI will be:

1. 2×10^-3 M

2. 1×10^-4 M

3. 1.6×10^-2 M

4. 4×10^-4 M

 Find the percentage hydrolysis of NaCN in a 0.1 M solution if the pH of the solution is 11.

1. 0.1%

2. 1.0%

3. 0.01%

4. 10%

How much water should be added to 400 mL of HCI solution in order to raise the pH by one unit?

Find the degree of dissociation of N₂O₄ at 100°C corresponding to vapour density 24.5:

1. 80%

2. 87.75%

3. 40.34%

4. 60%

For the equilibrium  SO₂CI₂(g) ⇌ SO₂(g) + CI₂(g)  volume is increased.
When the equilibrium is re-established then: 

1. amount of  SO₂(g)  will decrease

2. amount of  SO₂CI₂(g)  will increase

3. amount of CI₂(g)  will increase

4. amount of CI₂(g) will remain unchanged

In the reaction A(g) + 2B(g) ⇌ 2C(g) + D(g), the initial concentration of B is twice that of A and, at equilibrium, the concentrations of A and D are equal. The value of the equilibrium constant will be:

$\mathrm{Consider\; the\; given\; reaction:\; 2}\mathrm{HI}\stackrel{}{\rightleftharpoons }{\mathrm{H}}_2+{\mathrm{I}}_2$ 
At 22% dissociation of HI, what would be the value of equilibrium constant?

1. 0.04

2. 0.0198

3. 0.5

4. 1.2527

The degree of hydrolysis of the salt is independent of the concentration of a solution: 
1. NH₄CI
2. NH₄CN
3. (NH₄)₂SO₄
4. All of the above