Degree of Dissociation

Q. At ${30}^{\circ }C,K_p$ for the dissociation reaction:
$S{O}_{2}C{l}_2\left(g\right)\leftrightharpoons S{O}_2\left(g\right)+C{l}_2\left(g\right)is2.9x{10}^{-2}$~atm. If the total pressure is 1 atm, the degree of dissociation of $S{O}_{2}C{l}_{2}is(assume1-{\alpha }^2=1)$

1. $85\%$
2. $12\%$
3. $17\%$
4. $35\%$

Q. The degree of dissociation of water at ${25}^{\circ }C$ is $1.9\times {10}^{-7}$ and density is $1.0gc{m}^{-3}$ The ionic constant for water is :

1. $1.0\times {10}^{-10}$
2. $1.0\times {10}^{-14}$
3. $1.0\times {10}^{-16}$
4. $1.0\times {10}^{-8}$

Q. What will be the $H^{+}$ ion concentration of 0.01 M $HCN$ solution at equilibrium, if it is 20% ionised?

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

Q.

An aqueous solution of carbonic acid ($H_{2}C{O}_3$) contains

1. ($H_{2}C{O}_3)only$

2. $H_{2}C{O}_3,H^{+},HC{O}_3^{-},C{O}_3^{2-}$

3. $H_{2}C{O}_3,H^{+},HC{O}_3^{-}$

4. $H_{2}C{O}_3,C{O}_2,H^{+},HC{O}_3^{-},C{O}_3^{2-}$

Q. Consider a weak electrolyte, $A{B}_3$ having a concentration of 0.1 M in solution. If the degree of dissociation is 0.2, Calculate the ionisation constant $K_i$ of $A{B}_3$.

1. $2.4\times {10}^{-9}$
2. $5.4\times {10}^{-5}$
3. $1.4\times {10}^{-2}$
4. $3.4\times {10}^{-7}$

Q. Consider a reaction:
$S{O}_{2}C{l}_2\left(g\right)\rightleftharpoons S{O}_2\left(g\right)+C{l}_2\left(g\right)$
Initially only $S{O}_{2}C{l}_2\left(g\right)$ is present. The vapour density of an equilibrium mixture of this reaction is 45.
The degree of dissociation of $S{O}_{2}C{l}_2\left(g\right)$ is :

1. 0.75
2. 0.14
3. 0.5
4. 0.28

Q. If a $25mL$ $5.0\times {10}^{-4}MC{a}^{2+}$ solution and $25mL$ $2.5\times {10}^{-4}M{C}_2{O}_4^{2-}$ solution are mixed, then which of the following option is correct ?
Given: $K_{sp}\left(Ca{C}_2{O}_4\right)=2.3\times {10}^{-9}$.

1. Precipitate is formed
2. No precipitate is formed
3. Can't be determined.
4. None of the above

Q. Consider the following reaction :
$HI\left(g\right)\rightleftharpoons \frac{1}{2}{H}_2\left(g\right)+\frac{1}{2}{I}_2\left(g\right)$

At equilibrium, 40% of $HI$ is dissociated.
The value of $K_x$ (equilibrium constant in terms of mole fraction) is :

1. 1.25
2. 0.75
3. 0.25
4. 0.67

Q. Consider a weak electrolyte, $A{B}_3$ having a concentration of 0.1 M in solution. If the degree of dissociation is 0.2, Calculate the ionisation constant $K_i$ of $A{B}_3$.

1. $2.4\times {10}^{-9}$
2. $1.4\times {10}^{-2}$
3. $3.4\times {10}^{-7}$
4. $5.4\times {10}^{-5}$

Q. The unit of ionic product of water $\left(K_w\right)$ is:

1. $mol{L}^{-1}$
2. $mo{l}^2{L}^{-2}$
3. $Lmo{l}^{-1}$
4. $mo{l}^{-2}{L}^2$

Q. Consider a reaction:
$S{O}_{2}C{l}_2\left(g\right)\rightleftharpoons S{O}_2\left(g\right)+C{l}_2\left(g\right)$
Initially only $S{O}_{2}C{l}_2\left(g\right)$ is present. The vapour density of an equilibrium mixture of this reaction is 45.
The degree of dissociation of $S{O}_{2}C{l}_2\left(g\right)$ is :

1. 0.14
2. 0.75
3. 0.5
4. 0.28

Q. If ${\Lambda }_c$ for $N{H}_{4}OH$ is 11.5 $oh{m}^{-1}c{m}^{2}mo{l}^{-1}$, its degree of dissociation would be
(given that ${\lambda }^{\circ }N{H}_4^{+}$ = 73.4 and ${\lambda }^{\circ }O{H}^{-}$ = 197.6 $oh{m}^{-1}c{m}^{2}mo{l}^{-1}$ )

1. 0.0848
2. 0.0424
3. 0.0212
4. 0.004

Q. The % of dissociation of water at ${25}^{\circ }C$ is $1.9\times {10}^{-7}$ and density is $1.0gc{m}^{-3}$ The ionic constant for water is :

1. $1.0\times {10}^{-10}$
2. $1.0\times {10}^{-14}$
3. $1.0\times {10}^{-16}$
4. $1.0\times {10}^{-8}$

Q. At ${50}^{o}C,$ the self-ionisation constant (ionic product) of $N{H}_3$ is given as,
$K_{N{H}_3}=\left[N{H}_4^{+}\right]\left[N{H}_2^{-}\right]={10}^{-30}{M}^2$.
How many $N{H}_2^{-}$ ions are present per $m{m}^3$ of pure liquid ammonia?

1. $600ions/m{m}^3$
2. $6\times {10}^{5}ions/m{m}^3$
3. $6\times {10}^{4}ions/m{m}^3$
4. $6\times {10}^{3}ions/m{m}^3$

Q. 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 0.04 M solution of the carbonic acid

1. The concentration of $C{O}_3^{2-}$ 0.034 M.
2. The concentration of $C{O}_3^{2-}$ is greater than that of $HC{O}_3^{-}$
3. The concentrataion of $H^{+}$ and $HC{O}_3^{-}$ are approximately equal.
4. The concentration of $H^{+}$ is double that of $C{O}_3^{2-}$

Q. $0.020\text{g}$ of selenium vapours at equilibrium occupying a volume of $2.463\text{mL}$ at $1\text{atm}$ and ${27}^{\circ }$C.
The selenium is in a state of equilibrium according to the reaction
$3S{e}_2\left(g\right)\rightleftharpoons S{e}_6\left(g\right)$
What is the degree of association of selenium?
(Atomic weight of Se = 79 amu)

1. 0.205
2. 0.315
3. 0.14
4. 0.51

Q. If ${\Lambda }_c$ for $N{H}_{4}OH$ is 11.5 $oh{m}^{-1}c{m}^{2}mo{l}^{-1}$, its degree of dissociation would be
(given that ${\lambda }^{\circ }N{H}_4^{+}$ = 73.4 and ${\lambda }^{\circ }O{H}^{-}$ = 197.6 $oh{m}^{-1}c{m}^{2}mo{l}^{-1}$ )

1. 0.0848
2. 0.0424
3. 0.0212
4. 0.004

Q. Calculate the percent dissociation of $H_{2}S\left(g\right)$ if 0.1 mol of $H_{2}S$ is kept in a 0.4 litre vessel at 1000 K. For the reaction,
$2H_{2}S\left(g\right)\rightleftharpoons 2H_2\left(g\right)+S_2\left(g\right)$ the value of $K_c$ is $1\times {10}^{-6}$.

1. $2\%$
2. $20\%$
3. $200\%$
4. $50\%$

Q. What will be the $H^{+}$ ion concentration of 0.01 M $HCN$ solution at equilibrium, if it is 20% ionised?

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

Q.

When $0.004MN{a}_{2}S{O}_4$ is isotonic with 0.01M solution of glucose at same temperature.the apparent degree of dissociation of sodium sulphate is

1. 75%

2. 50%

3. 25%

4. 85%

Q.

For an equilibrium $H_{2}O\left(s\right)\rightleftharpoons H_{2}O\left(l\right)$, which of the following statements is true?

1. The pressure changes do not affect the equilibrium

2. More of ice melts if pressure on the system is increased

3. More of liquid freezes if pressure on the system is increased

4. The pressure changes may increase or decrease the degree of advancement of the reaction depending upon the temperature of the system

Q. 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 0.04 M solution of the carbonic acid

1. The concentration of $C{O}_3^{2-}$ 0.034 M.
2. The concentration of $C{O}_3^{2-}$ is greater than that of $HC{O}_3^{-}$
3. The concentrataion of $H^{+}$ and $HC{O}_3^{-}$ are approximately equal.
4. The concentration of $H^{+}$ is double that of $C{O}_3^{2-}$