At T ( K ) , if the ionization constants of HCOOH and HCN are 2 . 0 × 10 - 4 and 5 . 0 × 10 - 9 , respectively, the ionization constants of the corresponding conjugate bases, respectively, are

5 . 0 × 10 - 11 , 2 . 0 × 10 - 6

2 . 0 × 10 - 6 , 5 . 0 × 10 - 11

2 . 0 × 10 - 4 , 5 . 0 × 10 - 9

5 . 0 × 10 - 9 , 2 . 0 × 10 - 4

In aqueous solution, the ionization constants for carbonic acid are, K 1 = 4 .2 × 10 - 7 and K 2 = 4 .8 × 10 - 11 Select the correct statement for a saturated 0 . 034 M solution of the carbonic acid.

The concentration of H + and HCO 3 - are approximately equal

The concentration of C O 3 2 - is 0 . 034 M

The concentration of C O 3 2 - is greater than that of H C O 3 -

The concentration of H + is double that of C O 3 2 -

MEDIUM

Earn 100

Derive the expression of ostwarlds dilution law in the case of a weak electrolyte.

Important Questions on Ionic Equilibria

EASY

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

Match the following

Acid		Ionization constant, $K_{a}$
A)	Formic acid	I)	$4.9 \times 10^{- 10}$
B)	Niacin	II)	$1.5 \times 10^{- 5}$
C)	Hypochlorous acid	III)	$1.8 \times 10^{- 4}$
D)	Hydrocyanic acid	IV)	$3 \times 10^{- 8}$

The correct match is

MEDIUM

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

The degree of dissociation of

0.1 M

acid

HA

5 % .

The value of

K_{c}

HA

EASY

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

Match the following

List-1 Acid		List-2 Ka(ionization constant)
A)	$HCN$	I)	$6.8 \times 10^{- 4}$
B)	$H_{2} C_{2} O_{4}$	II)	$8.9 \times 10^{- 8}$
C)	$H_{2} S$	III)	$4.9 \times 10^{- 10}$
D)	Niacin	IV)	$5.6 \times 10^{- 2}$
		V)	$1.5 \times 10^{- 5}$

The correct match is

HARD

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

Sulphurous acid

(H_{2} {SO}_{3})

has

{Ka}_{1} = 1.7 \times 10^{- 2}

and

{Ka}_{2} = 6.4 \times 10^{- 8} .

The

pH

0.588 M H_{2} {SO}_{3}

is____________

(

Round off to the Nearest Integer

)

EASY

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

Ostwald's dilution law is applicable only for

MEDIUM

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

The solubility of

AgCl

will be maximum in which of the following?

HARD

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

Acetylsalicylic acid has

{pK}_{a}

value

3.5 .

The

pH

of gastric juice in human stomach is

2 - 3

and the pH in the small intestine is approximately

7.4 .

Then acetylsalicylic acid will be

MEDIUM

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$ .

Assertion $A$ :Phenolphthalein is a $pH$ dependent indicator, remains colourless in acidic solution and gives pink colour in basic medium

Reason $R$ : Phenolphthalein is a weak acid. It doesn't dissociate in basic medium.

In the light of the above statements, choose the most appropriate answer from the options given below

MEDIUM

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

{CH}_{3} COOH

1 %

ionised in its aqueous solution of

0.1 M

strength. Its

pOH

will be

EASY

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

K_{a}

values for acids

H_{2} {SO}_{3}, {HNO}_{2}, {CH}_{3} COOH

and

HCN

are respectively

1.3 \times 10^{- 2}, 4 \times 10^{- 4}, 1.8 \times 10^{- 5}

and

4 \times 10^{- 10},

which of the above acids produces stronger conjugate base in aqueous solution?

HARD

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

K_{a}

for butyric acid

(C_{3} H_{7} COOH)

2 \times 10^{- 5}

. The

pH

0.2 M

solution of butyric acid is____

\times 10^{- 1}

. (Nearest integer) [Given

\log 2 = 0.30

]

MEDIUM

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

0.004 M

{Na}_{2} {SO}_{4}

is isotonic with

0.01 M

glucose solution. The degree of dissociation of

{Na}_{2} {SO}_{4}

EASY

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

The

pH

0.1 M

solution of acetic acid will be [degree of dissociation of acetic acid is

0.0132

]

EASY

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

The acid dissociation constants of methanoic acid, monochloroethanoic acid and ethanoic acid are

K_{1}, K_{2}

and

K_{3}

respectively. If

K_{2} > K_{1} > K_{3}

, then

MEDIUM

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

T (K)

, if the ionization constants of

HCOOH

and

HCN

are

2.0 \times 10^{- 4}

and

5.0 \times 10^{- 9}

, respectively, the ionization constants of the corresponding conjugate bases, respectively, are

MEDIUM

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

10 mL

0.1 M {CH}_{3} {COO}^{-} {Na}^{+}

is mixed with

11 mL

0.1 M HCl

of the concentration of

{CH}_{3} {COO}^{-}

ion at equilibrium is, (take

K_{a} ({CH}_{3} COOH) = 10^{- 5}

)

MEDIUM

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

The degree of ionization of

0.4 M

Acetic acid will be

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

EASY

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

In aqueous solution, the ionization constants for carbonic acid are,

K_{1} = 4 .2 \times 10^{- 7}

and

K_{2} = 4 .8 \times 10^{- 11}

Select the correct statement for a saturated

0.034 M

solution of the carbonic acid.

EASY

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

0.005 M

acid solution has

5 pH

. The percentage ionization of acid is

MEDIUM

Chemistry>Physical Chemistry>Ionic Equilibria>Ionization of Weak Acids and Weak Bases

Write the steps of ionization of

H_{2} {SO}_{4}

Derive the expression of ostwarlds dilution law in the case of a weak electrolyte.

Important Questions on Ionic Equilibria

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