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CHXI07:EQUILIBRIUM

314540 Assertion :
$H_{3} {PO}_{4}$ and $H_{2} {SO}_{4}$ are known as polybasic acids.
Reason :
They have two or more than two protons per molecule of the acid.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

(i) $H_{2} {SO}_{4} ⇌ 2 H^{+} + {SO}_{4}^{2 -}$
(ii) $H_{3} {PO}_{4}^{-} ⇌ H^{+} + H_{2} {PO}_{4}^{-}$
$H_{2} {PO}_{4} ⇌ H^{+} + H_{2} {PO}_{4}^{-}$
$H_{2} {PO}_{4}^{2 -} ⇌ H^{+} + {PO}_{4}^{- 3}$
The acids which can produce more than one proton are called polybasic acids. So option (1) is correct.

CHXI07:EQUILIBRIUM

314541 Assertion :
The second dissociation constant of fumaric acid is greater than maleic acid.
Reason :
Higher the dissociation constant of acid, more is the acidic character.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

supporting img
Both fumaric and maleic acids have two ionisable $H^{+}$ ions i.e., protons. The maleate monoanion shows intramolecular $H$ -bonding, whereas fumarate monoanion shows intermolecular $H$ -bonding. Thus, fumarate monoanion requires more energy to give fumarate dianion. Hence, second dissociation constant of fumaric acid is more than that of maleic acid. So option (2) is correct.

CHXI07:EQUILIBRIUM

314542 Statement A :
Higher order ionisation constant $K a_{2} a n d K a_{3}$ are smaller than the lower order ionisation constant $K a_{1}$ of a polyprotic acid
Statement B :
It is more difficult to remove a positively charged proton from a negative ion due to Coulombic forces.

1 Statement A is correct but Statement B is incorrect.

2 Statement A is incorrect but Statement B is correct.

3 Both statements are correct.

4 Both Statements are incorrect.

Explanation:

Higher order ionisation constants $(K a_{2}$ , $K a_{3}$ ) are smaller than the lower order ionisation constant $(K a_{1})$ of a polyprotic acid. The reason for this is that, it is more difficult to remove a positively charged proton from a negative ion due to electrostatic forces. This can be seen in the case of removing a proton from the uncharged $H_{2} {CO}_{3}$ as compared from a negatively charged ${HCO}_{3}^{- 1}$ . So, the option (3) is correct.

CHXI07:EQUILIBRIUM

314540 Assertion :
$H_{3} {PO}_{4}$ and $H_{2} {SO}_{4}$ are known as polybasic acids.
Reason :
They have two or more than two protons per molecule of the acid.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

(i) $H_{2} {SO}_{4} ⇌ 2 H^{+} + {SO}_{4}^{2 -}$
(ii) $H_{3} {PO}_{4}^{-} ⇌ H^{+} + H_{2} {PO}_{4}^{-}$
$H_{2} {PO}_{4} ⇌ H^{+} + H_{2} {PO}_{4}^{-}$
$H_{2} {PO}_{4}^{2 -} ⇌ H^{+} + {PO}_{4}^{- 3}$
The acids which can produce more than one proton are called polybasic acids. So option (1) is correct.

CHXI07:EQUILIBRIUM

314541 Assertion :
The second dissociation constant of fumaric acid is greater than maleic acid.
Reason :
Higher the dissociation constant of acid, more is the acidic character.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

supporting img
Both fumaric and maleic acids have two ionisable $H^{+}$ ions i.e., protons. The maleate monoanion shows intramolecular $H$ -bonding, whereas fumarate monoanion shows intermolecular $H$ -bonding. Thus, fumarate monoanion requires more energy to give fumarate dianion. Hence, second dissociation constant of fumaric acid is more than that of maleic acid. So option (2) is correct.

CHXI07:EQUILIBRIUM

314542 Statement A :
Higher order ionisation constant $K a_{2} a n d K a_{3}$ are smaller than the lower order ionisation constant $K a_{1}$ of a polyprotic acid
Statement B :
It is more difficult to remove a positively charged proton from a negative ion due to Coulombic forces.

1 Statement A is correct but Statement B is incorrect.

2 Statement A is incorrect but Statement B is correct.

3 Both statements are correct.

4 Both Statements are incorrect.

Explanation:

Higher order ionisation constants $(K a_{2}$ , $K a_{3}$ ) are smaller than the lower order ionisation constant $(K a_{1})$ of a polyprotic acid. The reason for this is that, it is more difficult to remove a positively charged proton from a negative ion due to electrostatic forces. This can be seen in the case of removing a proton from the uncharged $H_{2} {CO}_{3}$ as compared from a negatively charged ${HCO}_{3}^{- 1}$ . So, the option (3) is correct.

CHXI07:EQUILIBRIUM

314540 Assertion :
$H_{3} {PO}_{4}$ and $H_{2} {SO}_{4}$ are known as polybasic acids.
Reason :
They have two or more than two protons per molecule of the acid.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

(i) $H_{2} {SO}_{4} ⇌ 2 H^{+} + {SO}_{4}^{2 -}$
(ii) $H_{3} {PO}_{4}^{-} ⇌ H^{+} + H_{2} {PO}_{4}^{-}$
$H_{2} {PO}_{4} ⇌ H^{+} + H_{2} {PO}_{4}^{-}$
$H_{2} {PO}_{4}^{2 -} ⇌ H^{+} + {PO}_{4}^{- 3}$
The acids which can produce more than one proton are called polybasic acids. So option (1) is correct.

CHXI07:EQUILIBRIUM

314541 Assertion :
The second dissociation constant of fumaric acid is greater than maleic acid.
Reason :
Higher the dissociation constant of acid, more is the acidic character.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

supporting img
Both fumaric and maleic acids have two ionisable $H^{+}$ ions i.e., protons. The maleate monoanion shows intramolecular $H$ -bonding, whereas fumarate monoanion shows intermolecular $H$ -bonding. Thus, fumarate monoanion requires more energy to give fumarate dianion. Hence, second dissociation constant of fumaric acid is more than that of maleic acid. So option (2) is correct.

CHXI07:EQUILIBRIUM

314542 Statement A :
Higher order ionisation constant $K a_{2} a n d K a_{3}$ are smaller than the lower order ionisation constant $K a_{1}$ of a polyprotic acid
Statement B :
It is more difficult to remove a positively charged proton from a negative ion due to Coulombic forces.

1 Statement A is correct but Statement B is incorrect.

2 Statement A is incorrect but Statement B is correct.

3 Both statements are correct.

4 Both Statements are incorrect.

Explanation:

Higher order ionisation constants $(K a_{2}$ , $K a_{3}$ ) are smaller than the lower order ionisation constant $(K a_{1})$ of a polyprotic acid. The reason for this is that, it is more difficult to remove a positively charged proton from a negative ion due to electrostatic forces. This can be seen in the case of removing a proton from the uncharged $H_{2} {CO}_{3}$ as compared from a negatively charged ${HCO}_{3}^{- 1}$ . So, the option (3) is correct.