The molar solubility of ${\mathrm{CaF}}_2$ $({\mathrm{K}}_{\mathrm{sp}}=5.3$ $\mathrm{\times }$ ${10}^{-11})$ in 0.1 M solution of NaF will be:

1.	$5.3$ $\mathrm{\times }$ ${10}^{-11}$ $\mathrm{mol}$ ${\mathrm{L}}^{-1}$	2.	$5.3$ $\mathrm{\times }$ ${10}^{-8}$ $\mathrm{mol}$ ${\mathrm{L}}^{-1}$
3.	$5.3$ $\mathrm{\times }$ ${10}^{-9}$ $\mathrm{mol}$ ${\mathrm{L}}^{-1}$	4.	$5.3$ $\mathrm{\times }$ ${10}^{-10}$ $\mathrm{mol}$ ${\mathrm{L}}^{-1}$

Which of the following cannot act both as a Bronsted acid and as a Bronsted base?

1. \(\mathrm{H C O_{3}^{-}}\)

2. \(\mathrm{NH_3}\)

3. \(\mathrm{HCl}\)

4. \(\mathrm{H S O_{4}^{-}}\)

1. H₃O⁺ and H₂F⁺, respectively.

2. OH^– and H₂F⁺, respectively.

3. H₃O⁺ and F^–, respectively.

4. OH^– and F^–, respectively.

pH of a saturated solution of $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ is 9. The solubility product $\left({\mathrm{K}}_{\mathrm{sp}}\right)$ of $\mathrm{Ca}{\left(\mathrm{OH}\right)}_2$ is:

1. $0.5\times {10}^{-10}$

2. $0.5\times {10}^{-15}$

3. $0.25\times {10}^{-10}$

4. $0.125\times {10}^{-15}$

Which composition will make the basic buffer?

The following pair constitutes a buffer is:

1. $HN{O}_2$ $and$ $NaN{O}_2$

2. $NaOH$ $and$ $NaCl$

3. $HN{O}_3$ $and$ $N{H}_{4}N{O}_3$

4. $HCl$ $and$ $KCl$

Which one of the following orders correctly represents the increasing acid strengths of the given acids?

1. $HOCl<HOClO<HOCl{O}_2<HOCl{O}_3$

2. $HOClO<HOCl<HOCl{O}_3<HOCl{O}_2$

3. $HOCl{O}_2<HOCl{O}_3<HOClO<HOCl$

4. $HOCl{O}_3<HOCl{O}_2<HOClO<HOCl$

The following equilibrium constants are given: 
N₂ + 3H₂ ⇌ 2NH₃; K₁ 
N₂ + O₂ ⇌ 2NO; K₂ 
H₂ + 1/2O₂ ⇌ H₂O; K₃ 

The equilibrium constant for the oxidation of NH₃ by oxygen to give NO is:

1. $K_2{K}_3^3/K_1$

2. $K_2{K}_3^2/K_1$

3. $K_2^2{K}_3/K_1$

4. $K_1{K}_2/K_3$ 

A weak acid, HA, has a K_a of 1.00×10^-5. If 0.100 mole of this acid is dissolved in one litre of water, the percentage of acid dissociated at equilibrium is closest to:

1. 99.0%

2. 1%

3. 99.9%

4. 0.100%