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K_a for HCN is 5 x 10^{- 10} at 25^o C. For maintaining a constant pH of 9, the volume of 5 M KCN solution required to be added to 10 mL of 2 M HCN solution is:

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Important Questions on Equilibrium

EASY

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

Among the following, the correct statement is

HARD

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

A solution of

0.1

mole of

{CH}_{3} {NH}_{2} (K_{b} = 5 \times 10^{- 4})

and

0.08 mole

HCl

is diluted to one litre, then the

pOH

of the solution is

(\log 1.25 = 0.1)

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

Which of the following mixtures will have the lowest pH at $298 K ?$

EASY

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

For a buffer of a mixture of

0.12 mol L^{- 1}

{CH}_{3} COOH

and

0.12 mol L^{- 1} {CH}_{3} COONa,

the buffer capacity is

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

Which will make basic buffer?

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

What will be the

pH

of solution formed by mixing

10 mL 0.1 {MNaH}_{2} {PO}_{4}

15 mL

0.1 {MNa}_{2} {HPO}_{4}

[Given:

{pK}_{1} = 2.12, {pK}_{2} = 7.2]

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

If the

pH

of a solution containing

10 mL

0.5 M {CH}_{3} COOH

and

10 mL

0.25 M NaOH

5

. What is the

{pK}_{a}

of the acid?

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

Which among the following pairs is not an acidic buffer?

HARD

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

3 g

of acetic acid is added to

250 m L

0.1 M H C l

and the solution made up to

500 m L

. To

20 m L

of this solution

\frac{1}{2} m L

5 M N a O H

is added. The

p H

of the solution is ________
[Given:

p K a

of acetic acid

= 4.75,

molar mass of acetic acid

60 g / m o l, \log 3 = 0.4771

, Neglect any changes in volume]

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

An acidic buffer is obtained on mixing:

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

In order to prepare a buffer solution of

pH 5.74

, sodium acetate is added to acetic acid. If the concentration of acetic acid in the buffer is

1.0 M,

the concentration of sodium acetate in the buffer is ______

M .

(Round off to the Nearest Integer).

[Given : pKa (acetic acid) = 4.74]

EASY

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

Addition of sodium hydroxide solution to a weak acid (HA) results in a buffer of pH 6. If ionization constant of HA is

10^{- 5}

, the ratio of salt to acid concentration in the buffer solution will be:

HARD

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

The negative logarithm of dissociation constant of

{NH}_{4} OH

4.745

. A buffer solution contains

0.035

mole

{NH}_{4} OH

and

0.35

mole

{NH}_{4} Cl

per litre. The

pH

of the buffer solution is

HARD

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

A buffer solution can be prepared by mixing equal volumes of

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

The

{OH}^{-}

concentration in a mixture of

5.0 mL

0.0504 M {NH}_{4} Cl

and

2 mL

0.0210 M {NH}_{3}

solution is

x \times 10^{- 6} M

. The value of

x

is (Nearest integer) [Given

K_{w} = 1 \times 10^{- 14}

and

K_{b} = 1.8 \times 10^{- 5}]

EASY

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

Calculate the

pH

of a solution containing

0.2 M {CH}_{3} COOH

and

0.1 M {CH}_{3} COONa .

The

K_{a}

{CH}_{3} COOH = 1.8 \times 10^{- 5} (- \log (1.8 \times 10^{- 5}) = 4.74)

EASY

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

If the molar concentrations of base and its conjugate acid are same, then

pOH

of the buffer solution is

HARD

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

A solution of $0.1 M$ weak base $(B)$ is titrated with $0.1 M$ of a strong acid $(HA)$ . The variation of $pH$ of the solution with the volume of $HA$ added is shown in the figure below. What is the ${pK}_{b}$ of the base? The neutralisation reaction is given by $B + HA \to {BH}^{+} + A^{-}$ .

Question Image

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

50 mL

0 .2 M

ammonia solution is treated with

25 mL of 0.2 M HCl

. If

{pK}_{b}

of ammonia solution is

4.75

, the

pH

of the mixture will be:

EASY

Chemistry>Physical Chemistry>Equilibrium>Buffer Solutions

Which one of the following pairs of solution is not an acidic buffer?

Ka for HCN is 5 x 10 - 10 at 25o C. For maintaining a constant pH of 9, the volume of 5 M KCN solution required to be added to 10 mL of 2 M HCN solution is:

Important Questions on Equilibrium

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K_a for HCN is 5 x 10^{- 10} at 25^o C. For maintaining a constant pH of 9, the volume of 5 M KCN solution required to be added to 10 mL of 2 M HCN solution is: