Given below are two statements: 

The ratio of the concentration of salt and acid for preparing a buffer solution of pH 6 by mixing sodium acetate and acetic acid will be: (K_a=10^-5)

1. 1:10

2. 10:1

3. 100:1

4. 1:100

The pK_a of HCN is 9.30. The pH of a solution prepared by mixing 2.5 moles of KCN and 2.5 moles of HCN in water and making up the total volume to 500 ml will be:

The basic buffer solution among the following is: 

1. ${\mathrm{NH}}_4\mathrm{Cl}+{\mathrm{NH}}_4\mathrm{OH}$

2. $\mathrm{NaCl}+\mathrm{NaOH}$

3. ${\mathrm{NH}}_4\mathrm{Cl}+{\mathrm{CH}}_3\mathrm{COOH}$

4. ${\mathrm{CH}}_3\mathrm{COONa}+{\mathrm{CH}}_3\mathrm{COOH}$

At 25°C, the pH of a solution containing 0.10 M sodium acetate and 0.03 M acetic acid will be:

[pK_a value of ${\mathrm{CH}}_3\mathrm{COOH}=4.57$]

1. 3.24

2. 4.59

3. 5.09

4. 6.67

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)

Find the pair of solutions that can be mixed to prepare an acidic buffer.

1. Sodium chloride and sodium hydroxide

2. Sulphuric acid and sodium sulphate

3. Ammonium chloride and ammonium nitrate

4. Ammonium acetate and acetic acid

Find the pH of a buffer prepared by mixing 10 mL of 1.0 M CH₃COOH with 20 mL of 0.5 M CH₃COONa and diluting the mixture to 100 mL with distilled water. Given:

pKₐ(CH₃COOH) = 4.76

1. 5.21

2. 4.76

3. 4.34

4. 5.35

Which of the following combinations can be used to prepare a buffer solution?

I. Sodium acetate and acetic acid in water

II. Sodium acetate and hydrochloric acid in water

III. Ammonia and ammonium chloride in water

IV. Ammonia and sodium hydroxide in water.

1. I, III, IV

2. III, IV

3. I, II, IV

4. I,  III

The concentration of $\left[{\mathrm{H}}^{+}\right]$ ion in a solution containing 0.1 M HCN and 0.2 M NaCN will be:

(${\mathrm{K}}_{\mathrm{a}}$ for HCN = $6.2\times {10}^{-10}$)

1. 3.1$\times {10}^{10}$

2. $6.2\times {10}^5$

3.$$ $6.2\times {10}^{-10}$

4. $3.1\times {10}^{-10}$