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CHXI07:EQUILIBRIUM

314737 Equimolar solutions of the following compounds are prepared separately in water. Which will have the lowest $pH$ value?

1

{BeCl}_{2}

2

{SrCl}_{2}

3

{CaCl}_{2}

4

{MgCl}_{2}

Explanation:

Metal halide on hydrolysis with water form corresponding hydroxides.
The basic strength of hydroxide increases as we move down in a group. This is because of the increase in size which results in decrease of ionisation energy which weakens the strength of $M - O$ bonds in $MOH$ and thus increases the basic strength.
$\underset{Amphoteric}{Be (OH)_{2}} \underset{Weak base}{Mg (OH)_{2}} Ca (OH)_{2} \underset{Strong base}{Sr (OH)_{2}} Ba (OH)_{2}$
Hence, $Be (OH)_{2}$ will have lowest $pH$ .

JEE - 2013

CHXI07:EQUILIBRIUM

314738 A salt of weak acid and weak base undergoes

1 Only cationic hydrolysis

2 Only anionic hydrolysis

3 Both cationic and anionic hydrolysis

4 No hydrolysis

CHXI07:EQUILIBRIUM

314739 Read statement-A and statement-B carefully to mark the correct options given below.
Statement A :
: Aqueous solution of ammonium carbonate is basic.
Statement B :
:Acidic/basic nature of salt solution of a salt of weak acid and weak base depends on $K_{a}$ and $K_{b}$ values of acid and the base forming it.

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:

${NH}_{4} OH : {pK}_{b} = 4.74$
$H_{2} {CO}_{3} : {pK}_{a} = 6.35$
As ${pK}_{b} > {pK}_{a}$ , it's aqueous solution is basic. pH of salt of weak acid & weak base is given by
$pH = 7 + \frac{1}{2} {pK}_{a} - \frac{1}{2} {pK}_{b}$
It means pH depends on $K_{a} & K_{b}$ values.So, the correct option is (3).

JEE Main - 2024

CHXI07:EQUILIBRIUM

314740 $pH$ of water is 7. When a substance $X$ is dissolved in water, the $pH$ becomes 13. The substance $X$ is a salt of

1 Strong acid and strong base

2 Weak acid and weak base

3 Strong acid and weak base

4 Weak acid and strong base

Explanation:

Salt if $SB$ and WA increases $pH$ .

CHXI07:EQUILIBRIUM

314737 Equimolar solutions of the following compounds are prepared separately in water. Which will have the lowest $pH$ value?

1

{BeCl}_{2}

2

{SrCl}_{2}

3

{CaCl}_{2}

4

{MgCl}_{2}

Explanation:

Metal halide on hydrolysis with water form corresponding hydroxides.
The basic strength of hydroxide increases as we move down in a group. This is because of the increase in size which results in decrease of ionisation energy which weakens the strength of $M - O$ bonds in $MOH$ and thus increases the basic strength.
$\underset{Amphoteric}{Be (OH)_{2}} \underset{Weak base}{Mg (OH)_{2}} Ca (OH)_{2} \underset{Strong base}{Sr (OH)_{2}} Ba (OH)_{2}$
Hence, $Be (OH)_{2}$ will have lowest $pH$ .

JEE - 2013

CHXI07:EQUILIBRIUM

314738 A salt of weak acid and weak base undergoes

1 Only cationic hydrolysis

2 Only anionic hydrolysis

3 Both cationic and anionic hydrolysis

4 No hydrolysis

CHXI07:EQUILIBRIUM

314739 Read statement-A and statement-B carefully to mark the correct options given below.
Statement A :
: Aqueous solution of ammonium carbonate is basic.
Statement B :
:Acidic/basic nature of salt solution of a salt of weak acid and weak base depends on $K_{a}$ and $K_{b}$ values of acid and the base forming it.

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:

${NH}_{4} OH : {pK}_{b} = 4.74$
$H_{2} {CO}_{3} : {pK}_{a} = 6.35$
As ${pK}_{b} > {pK}_{a}$ , it's aqueous solution is basic. pH of salt of weak acid & weak base is given by
$pH = 7 + \frac{1}{2} {pK}_{a} - \frac{1}{2} {pK}_{b}$
It means pH depends on $K_{a} & K_{b}$ values.So, the correct option is (3).

JEE Main - 2024

CHXI07:EQUILIBRIUM

314740 $pH$ of water is 7. When a substance $X$ is dissolved in water, the $pH$ becomes 13. The substance $X$ is a salt of

1 Strong acid and strong base

2 Weak acid and weak base

3 Strong acid and weak base

4 Weak acid and strong base

Explanation:

Salt if $SB$ and WA increases $pH$ .

CHXI07:EQUILIBRIUM

314737 Equimolar solutions of the following compounds are prepared separately in water. Which will have the lowest $pH$ value?

1

{BeCl}_{2}

2

{SrCl}_{2}

3

{CaCl}_{2}

4

{MgCl}_{2}

Explanation:

Metal halide on hydrolysis with water form corresponding hydroxides.
The basic strength of hydroxide increases as we move down in a group. This is because of the increase in size which results in decrease of ionisation energy which weakens the strength of $M - O$ bonds in $MOH$ and thus increases the basic strength.
$\underset{Amphoteric}{Be (OH)_{2}} \underset{Weak base}{Mg (OH)_{2}} Ca (OH)_{2} \underset{Strong base}{Sr (OH)_{2}} Ba (OH)_{2}$
Hence, $Be (OH)_{2}$ will have lowest $pH$ .

JEE - 2013

CHXI07:EQUILIBRIUM

314738 A salt of weak acid and weak base undergoes

1 Only cationic hydrolysis

2 Only anionic hydrolysis

3 Both cationic and anionic hydrolysis

4 No hydrolysis

CHXI07:EQUILIBRIUM

314739 Read statement-A and statement-B carefully to mark the correct options given below.
Statement A :
: Aqueous solution of ammonium carbonate is basic.
Statement B :
:Acidic/basic nature of salt solution of a salt of weak acid and weak base depends on $K_{a}$ and $K_{b}$ values of acid and the base forming it.

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:

${NH}_{4} OH : {pK}_{b} = 4.74$
$H_{2} {CO}_{3} : {pK}_{a} = 6.35$
As ${pK}_{b} > {pK}_{a}$ , it's aqueous solution is basic. pH of salt of weak acid & weak base is given by
$pH = 7 + \frac{1}{2} {pK}_{a} - \frac{1}{2} {pK}_{b}$
It means pH depends on $K_{a} & K_{b}$ values.So, the correct option is (3).

JEE Main - 2024

CHXI07:EQUILIBRIUM

314740 $pH$ of water is 7. When a substance $X$ is dissolved in water, the $pH$ becomes 13. The substance $X$ is a salt of

1 Strong acid and strong base

2 Weak acid and weak base

3 Strong acid and weak base

4 Weak acid and strong base

Explanation:

Salt if $SB$ and WA increases $pH$ .

CHXI07:EQUILIBRIUM

314737 Equimolar solutions of the following compounds are prepared separately in water. Which will have the lowest $pH$ value?

1

{BeCl}_{2}

2

{SrCl}_{2}

3

{CaCl}_{2}

4

{MgCl}_{2}

Explanation:

Metal halide on hydrolysis with water form corresponding hydroxides.
The basic strength of hydroxide increases as we move down in a group. This is because of the increase in size which results in decrease of ionisation energy which weakens the strength of $M - O$ bonds in $MOH$ and thus increases the basic strength.
$\underset{Amphoteric}{Be (OH)_{2}} \underset{Weak base}{Mg (OH)_{2}} Ca (OH)_{2} \underset{Strong base}{Sr (OH)_{2}} Ba (OH)_{2}$
Hence, $Be (OH)_{2}$ will have lowest $pH$ .

JEE - 2013

CHXI07:EQUILIBRIUM

314738 A salt of weak acid and weak base undergoes

1 Only cationic hydrolysis

2 Only anionic hydrolysis

3 Both cationic and anionic hydrolysis

4 No hydrolysis

CHXI07:EQUILIBRIUM

314739 Read statement-A and statement-B carefully to mark the correct options given below.
Statement A :
: Aqueous solution of ammonium carbonate is basic.
Statement B :
:Acidic/basic nature of salt solution of a salt of weak acid and weak base depends on $K_{a}$ and $K_{b}$ values of acid and the base forming it.

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:

${NH}_{4} OH : {pK}_{b} = 4.74$
$H_{2} {CO}_{3} : {pK}_{a} = 6.35$
As ${pK}_{b} > {pK}_{a}$ , it's aqueous solution is basic. pH of salt of weak acid & weak base is given by
$pH = 7 + \frac{1}{2} {pK}_{a} - \frac{1}{2} {pK}_{b}$
It means pH depends on $K_{a} & K_{b}$ values.So, the correct option is (3).

JEE Main - 2024

CHXI07:EQUILIBRIUM

314740 $pH$ of water is 7. When a substance $X$ is dissolved in water, the $pH$ becomes 13. The substance $X$ is a salt of

1 Strong acid and strong base

2 Weak acid and weak base

3 Strong acid and weak base

4 Weak acid and strong base

Explanation:

Salt if $SB$ and WA increases $pH$ .