Calculate the pH of a buffer solution consisting of 0 . 4 M CH 3 COOH and 0 . 4 M CH 3 COONa . What is the change in the pH after adding 0 . 01 mol of HCl to 500 ml of the above buffer solution. Assume that the addition of HCl causes negligible change in the volume. Given: K a = 1 . 8 × 10 - 5 .

CH 3 COOH aq ⇋ CH 3 COO - aq + H + aq CH 3 COONa aq ⇋ CH 3 COO - aq + Na + aq Given, 0 . 4 M CH 3 COONa and 0 . 4 M CH 3 COOH K a = 1 . 8 × 10 - 5 Therefore, H + = K a CH 3 COOH CH 3 COO - H + = 1 . 8 × 10 - 5 × 0 . 4 0 . 4 = 1 . 8 × 10 - 5 Addition of 0 . 01 mol HCl to 500 mL of buffer. H + = 0 . 01 mol 500 mL = 0 . 01 mol 0 . 5 L = 0 . 02 M

Concentration of the Ag + ions in a saturated solution of Ag 2 C 2 O 4 is 2 . 24 × 10 - 4 mol L - 1 solubility product of Ag 2 C 2 O 4 is

5 . 619 × 10 – 12 mol 3 L - 3

HARD

12th Tamil Nadu Board

IMPORTANT

Earn 100

$K_{b}$ for ${NH}_{4} OH$ is $1.8 \times 10^{- 5}$ . Calculate the percentage of ionisation of $0.06 M$ ammonium hydroxide solution.

Important Questions on Ionic Equilibrium

MEDIUM

12th Tamil Nadu Board

IMPORTANT

Chemistry Standard 12 Vol II>Chapter 1 - Ionic Equilibrium>Evaluate yourself - 8>Q 1

Explain the buffer action in a basic buffer containing equimolar ammonium hydroxide and ammonium chloride.

HARD

12th Tamil Nadu Board

IMPORTANT

Chemistry Standard 12 Vol II>Chapter 1 - Ionic Equilibrium>Evaluate yourself - 8>Q 1

Calculate the

pH

of a buffer solution consisting of

0.4 M {CH}_{3} COOH

and

0.4 M {CH}_{3} COONa

. What is the change in the

pH

after adding

0.01 mol

HCl

500 ml

of the above buffer solution. Assume that the addition of

HCl

causes negligible change in the volume. Given:

(K_{a} = 1.8 \times 10^{- 5})

HARD

12th Tamil Nadu Board

IMPORTANT

Chemistry Standard 12 Vol II>Chapter 1 - Ionic Equilibrium>Evaluate yourself - 9>Q 1

How can you prepare a buffer solution of

pH 9

. You are provided with

0.1 M {NH}_{4} OH

solution and ammonium chloride crystals. (Given:

{pK}_{b}

for

{NH}_{4} OH

4.7

25 ° C

HARD

12th Tamil Nadu Board

IMPORTANT

Chemistry Standard 12 Vol II>Chapter 1 - Ionic Equilibrium>Evaluate yourself - 9>Q 2

What volume of

0.6 M

sodium formate solution is required to prepare a buffer solution of

pH 4.0

by mixing it with

100 ml

0.8 M

formic acid. (Given:

{pK}_{a}

, for formic acid is

3.75

HARD

12th Tamil Nadu Board

IMPORTANT

Chemistry Standard 12 Vol II>Chapter 1 - Ionic Equilibrium>Evaluate yourself - 10>Q 1

Calculate the

i) hydrolysis constant,

ii) degree of hydrolysis and

iii) $pH$ of $0.05 M$ sodium carbonate solution $({pK}_{a}$ for ${HCO}_{3}^{-}$ is $10.26$ ).

HARD

12th Tamil Nadu Board

IMPORTANT

Chemistry Standard 12 Vol II>Chapter 1 - Ionic Equilibrium>EVALUATION>Q 1

Concentration of the

{Ag}^{+}

ions in a saturated solution of

{Ag}_{2} C_{2} O_{4}

2.24 \times 10^{- 4} mol L^{- 1}

solubility product of

{Ag}_{2} C_{2} O_{4}

HARD

12th Tamil Nadu Board

IMPORTANT

Chemistry Standard 12 Vol II>Chapter 1 - Ionic Equilibrium>EVALUATION>Q 2

Following solutions were prepared by mixing different volumes of $NaOH$ of $HCl$ different concentrations

(i) $60 mL \frac{M}{10} HCl + 40 mL \frac{M}{10} NaOH$ (ii) $55 mL \frac{M}{10} HCl + 45 mL \frac{M}{10} NaOH$

(iii) $75 mL \frac{M}{5} HCl + 25 mL \frac{M}{5} NaOH$ (iv) $100 mL \frac{M}{10} HCl + 100 mL \frac{M}{10} NaOH$

$pH$ of which one of them is equal to $1$ ?

HARD

12th Tamil Nadu Board

IMPORTANT

Chemistry Standard 12 Vol II>Chapter 1 - Ionic Equilibrium>EVALUATION>Q 3

The solubility of

{BaSO}_{4}

in water is

2.42 \times 10^{- 3} {gL}^{- 1}

298 K

. The value of its solubility product

(K_{sp})

will be(Given molar mass of

{BaSO}_{4}

= 233 {gmol}^{- 1}

Kb for NH4OH is 1.8×10-5. Calculate the percentage of ionisation of 0.06M ammonium hydroxide solution.

Important Questions on Ionic Equilibrium

Learn and Prepare for any exam you want !

$K_{b}$ for ${NH}_{4} OH$ is $1.8 \times 10^{- 5}$ . Calculate the percentage of ionisation of $0.06 M$ ammonium hydroxide solution.