Introduction and Degree of Hydrolysis

Q.

pH value of a solution, whose hydronium ion concentration is $6.2\times {10}^{-9}$

mol/l, is

1. 6.21

2. 7.21

3. 7.75

4. 8.21

Q.

A sample of 100 ml of 0.10 M acid HA $(K_a=1\times {10}^{-5})$ is titrated with standard 0.10 M KOH.How many ml of KOH will have to be added when the pH in the titration flask will be 5.00 ?

1. 0

2. 10

3. 100

4. 50

Q.

Calculate the pH of an aqueous solution of $1.0M$ ammonium formate assuming complete dissociation. ($p_{Ka}$ of formic acid = 3.8 and $p_{Kb}$ of ammonia = 4.8)

1. 7.5

2. 6

3. 6.5

4. 7.2

Q. If $K_a=1.8\times {10}^{-5}$, calculate the degree of hydrolysis of 0$.1M$ solution of sodium acetate at ${25}^{\circ }C$:

1. $7.45\times {10}^{-5}$
2. $7.45\times {10}^{-3}$
3. $7.45\times {10}^{-1}$
4. $5.5\times {10}^{-2}$

Q. What is the difference between the terms hydrolysis and hydration?

Q.

A solution of NaCN is

1. Alkaline in nature

2. Neutral in nature

3. Amphoteric in nature

4. Acidic in nature

Q.

Hydrolysis is the reverse of:

1. ionization

2. neutralization

3. acidification

4. saponification

Q.

In an attempted determination of the solubility product constant of $T{I}_{2}S$ the solubility of this compound in pure $C{O}^{2-}$ free water was determined as $6.3\times {10}^{-6}mol/L$. Assume that the dissolved sulfidehydrolyzes almost completely to $H{S}^{-}$ and that the further hydrolysis to $H_{2}S$ can be neglected. What is the computed $K_{sp}$ ?

1. 

2. 3.5 × 10-25

3. 

4. 

Q. Which of the following is true for autocatalysis?

Q.

What would be the hydrogen ion concentration in a solution containing 0.04 mole of acetic acid and 0.05 mole of sodium acetate in 500 ml of the solution?
Dissociation constant for acetic acid is 1.8 x ${10}^{-5}$.
The [ $H^{+}$] is:

1. 1.44 $\times$ ${10}^{-5}$

2. 14.5 $\times$ ${10}^{-9}$

3. 3.88 $\times$ ${10}^{-2}$

4. none of the above

Q.

The solution of a salt of a weak acid and weak base will have $pH$ -

($K_b$ = ${10}^{-6}$ ; $K_a$ = ${10}^{-4}$)

1. 8

2. 7

3. 6

4. 4

Q.

One or both the ions of a salt react with water to produce acidic, basic or neutral solution. This process is called:

1. neutralisation

2. ionisation

3. saponification

4. hydrolysis

Q. What is the $pH$ of $0.01MNaHC{O}_3$ ?
Given : $K_{a_1}and{K}_{a_2}$ for $H_{2}C{O}_3$ are $4.5\times {10}^{-7}and4.7\times {10}^{-11}$ respectively at $25{}^{o}C$.

1. 5.66
2. 8.33
3. 10.57
4. 6.33

Q. $HX$ is a weak acid $(K_a={10}^{-5}).$ It forms a salt $NaX$ $\left(0.1M\right)$ on reacting with caustic soda. What is the percentage of degree of hydrolysis (h) of $NaX$ ?

1. 0.01
2. 0.1
3. 0.001
4. None of the above

Q. The $pH$ of $0.1M$ solution of aniline is $8.8$. Its $p{K}_b$ value will be:

1. $7.82$
2. $6.18$
3. $9.40$
4. $8.40$

Q. The $pH$ of a $0.02\text{M}N{H}_{4}Cl$ solution will be:
[Given: $K_b\left(N{H}_{4}OH\right)={10}^{-5}$ and $\log 2=0.301$]

1. $2.65$
2. $4.35$
3. $4.65$
4. $5.35$

Q.

Ionization constants of weak acid HA and weak base BOH are $3.0\times {10}^{-7}$ each at 298 K. The percent degree of hydrolysis of their salt at the dilution of 10 L is :

1. 40

2. 50

3. 75

4. 25

Q.

An aqueous solution of Copper (II) sulphate pentahydrate turns blue litmus red. It is due to the

1. presence of Cu²⁺ ions

2. presence of SO₄^2– ions

3. hydrolysis of Cu²⁺ ions

4. hydrolysis of SO₄^2– ions

Q. Calculate the pH of a solution which is ${10}^{-1}MinHCland{10}^{-3}MinC{H}_{3}COOH[K_a=2\times {10}^{-3}]$

1. 2
2. 4
3. 1
4. 3

Q. $\%$ hydrolysis of $0.1MC{H}_{3}COON{H}_4$ when $K_a=K_b=1.8\times {10}^{-5}$ is -

1. $0.55$
2. $7.63$
3. $0.55\times {10}^{-2}$
4. $7.63\times {10}^{-3}$

Q. Calculate the percentage of hydrolysis in $0.003M$ aqueous solution of $NaOCN$. $K_a$ for $HOCN=3.33\times {10}^{-4}$.

1. 0.001
2. 0.01
3. 0.02
4. 0.1

Q. If $p{K}_b$ for the fluoride ion at ${25}^{\circ }C$ is 10.83, the ionization constant of hydrofluoric acid in water at this temperature is
Given : $antilog(-10.83)=1.479\times {10}^{-11}$

1. $1.74\times {10}^{-5}$
2. $3.52\times {10}^{-3}$
3. $6.76\times {10}^{-4}$
4. $5.38\times {10}^{-2}$

Q. If $p{K}_{a_1},p{K}_{a_2}andp{K}_{a_3}$ of $H_{3}P{O}_4$ are 2.2, 7.2 and 12.3 respectively. The $pH$ of $0.1M$ $N{a}_{2}HP{O}_4$ solution will be:

1. 7.2
2. 12.3
3. 8.5
4. 9.75

Q. Four solutions of $N{H}_{4}Cl$ are taken with concentrations $1M,0.1M,0.01Mand0.001M$. Their degree of hydrolysis are $h_1,h_2,h_3$ and $h_4$. What is the decreasing order of degree of hydrolysis ?

1. $h_1>h_2>h_3>h_4$
2. $h_1=h_2=h_3=h_4$
3. $h_4>h_3>h_2>h_1$
4. $\text{None of these}$

Q.

Calculate the pH of an aqueous solution of $1.0M$ ammonium formate assuming complete dissociation. ($p_{Ka}$ of formic acid = 3.8 and $p_{Kb}$ of ammonia = 4.8)

1. 7.2

2. 7.5

3. 6

4. 6.5

Q. For a ammonium chloride solution in water, the given equilibrium reaction occur:
$N{H}_4^{+}\left(aq\right)+H_{2}O\left(l\right)\stackrel{hydrolysis}{\rightleftharpoons }N{H}_{4}OH\left(aq\right)+H^{+}\left(aq\right)$
Which of the following describes correct relation ?

1. $K_h=\frac{K_w}{K_b}$
2. $K_h=K_w\times K_b$
3. $K_h=\frac{K_b}{K_w}$
4. None of the above

Q.

A solution of NaCN is

1. Acidic in nature

2. Alkaline in nature

3. Neutral in nature

4. Amphoteric in nature

Q. Calculate the hydrolysis constant of a salt containing $N{O}_2^{-}$ ion. If $K_a$ for $HN{O}_2=4.5\times {10}^{-10}$.

1. $2.8\times {10}^{-6}$
2. $20.5\times {10}^{-5}$
3. $2.2\times {10}^{-5}$
4. $1.1\times {10}^{-3}$

Q. Consider the reactions
$\left(i\right)CO\left(g\right)+H_{2}O\left(g\right)\rightleftharpoons C{O}_2\left(g\right)+H_2\left(g\right);K_1\left(ii\right)C{H}_4\left(g\right)+H_{2}O\left(g\right)\rightleftharpoons CO\left(g\right)+3H_2\left(g\right);K_2\left(iii\right)C{H}_4\left(g\right)+2H_{2}O\left(g\right)\rightleftharpoons C{O}_2\left(g\right)+4H_2\left(g\right);K_3$
which of the following is correct?

1. $K_3=K_1/K_2$
2. $K_3=K_1^2/K_2^{3-}$
3. $K_3=K_1{K}_2$
4. $K_3=K_1\sqrt{K_2}$

Q. If $K_a=1.8\times {10}^{-5}$, calculate the degree of hydrolysis of 0$.1M$ solution of sodium acetate at ${25}^{\circ }C$:

1. $7.45\times {10}^{-5}$
2. $7.45\times {10}^{-3}$
3. $7.45\times {10}^{-1}$
4. $5.5\times {10}^{-2}$