Which of the following cannot act as a buffer? 
1. NaH₂PO₄ + H₃PO₄
2. NH₄OH + NH₄CI
3. NaOH + CH₃COONa
4. Both (1) & (3)

If solubility product of Ca${\left(\mathrm{OH}\right)}_2 \mathrm{is} {10}^{-11}$, the pH at which $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ precipitate from a solution containing decimolar concentration of ${\mathrm{Ca}}^{2+}$ is

1. <5

2. 9<pH<5

3. >9

4. 9<pH>7

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

If the pH of 0.1 M NaCN solution is 11, then the percentage hydrolysis will be:

1. 0.1%

2. 1%

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?

Vapour density of ${\mathrm{N}}_2{\mathrm{O}}_4$ when heated to $100°\mathrm{C}$ becomes 24.5. its degree of dissociation at this temperature is

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:

$2\mathrm{HI}\stackrel{}{\rightleftharpoons }{\mathrm{H}}_2+{\mathrm{I}}_2$ for 22% dissociation what would be the value of equilibrium constant?

1. 0.04

2. 0.0198

3. 0.5

4. 1.2527