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. $0.125\times {10}^{-15}$

The following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations :

A)  $60$ $mL$ $\frac{M}{10}HCI$ $$ $+$ $40$ $mL$ $\frac{M}{10}NaOH$
B)   $55$ $mL$ $\frac{M}{10}HCI$ $$ $+$ $45$ $mL$ $\frac{M}{10}NaOH$
C)  $75$ $mL$ $\frac{M}{5}HCI$ $$ $+$ $25$ $mL$ $\frac{M}{5}NaOH$
D)  $100$ $mL$ $\frac{M}{10}HCI$ $$ $+$ $100$ $mL$ $\frac{M}{10}NaOH$

pH of which one of them will be equal to 1?

1. B
2. A
3. D
4. C

When equal volumes of 0.1 M NaOH and 0.01 M HCl are mixed, the pH of the resulting solution will be:

Which of the following salts will give the highest pH in water?
1. KCl
2. NaCl
3. Na₂CO₃
4. CuSO₄

Equimolar solutions of the following substances were prepared separately. Which one of these will record the highest pH value?

1. \(\mathrm{B a C l_{2}}\)
2. \(\mathrm{A l C l_{3}}\)
3. \(\mathrm{L i C l}\)
4. \(\mathrm{B e C l_{2}}\)${\mathrm{}}_{}$

What is the [OH^-] in the final solution prepared by mixing 20.0 mL of 0.050 M HCl with 30.0 mL of 0.10 M Ba(OH)₂?

1. 0.10 M

2. 0.40 M

3. 0.0050 M

4. 0.12 M

Equal volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the H⁺ ion concentration in the mixture?
1. $1.11\times {10}^{-4}$ $\mathrm{M}$
2. $3.7\times {10}^{-4}$ $\mathrm{M}$
3. $3.7\times {10}^{-3}$ $\mathrm{M}$
4. $1.11\times {10}^{-3}$ $\mathrm{M}$