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

 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?

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:

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

The dissociation of solid ${\mathrm{NH}}_4\mathrm{SH}$ in a closed container produces a pressure of 4 atm at $95°\mathrm{C}$, then ${\mathrm{K}}_{\mathrm{p}}$ for the reaction will be:

${\mathrm{NH}}_4\mathrm{SH}\left(\mathrm{s}\right)\stackrel{}{\rightleftharpoons }{\mathrm{NH}}_3\left(\mathrm{g}\right)+{\mathrm{H}}_2\mathrm{S}\left(\mathrm{g}\right)$

Calculate the number of H⁺ ions present in 1 mL of a solution having pH = 4.

($N_A=$ $Avogadro\text{'}s$ $number$)

1. \(10^{-7} N_A\)
2. \(10^{-8} N_A\)
3. \(10^{-16} N_A\)
4. \(10^{-14} N_A\)

Find the ratio [Salt]/[Acid] in an acidic buffer having pH = 5.7 and pKₐ = 5.0.
1. Three (3)
2. Four (4)
3. Five (5)
4. Six (6)

The addition of NH₄Cl to an aqueous solution of NH₄OH introduces a common ion (NH₄⁺). What is the effect on the pH of the solution?