Effective Equilibrium Constant

Q. The equilibrium constant for the reaction: $F{e}^{3+}\left(aq\right)+SC{N}^{-}\left(aq\right)\rightleftharpoons FeSC{N}^{2+}\left(aq\right)$ is 140 at 298 K.
The Equilibrium constant for the reaction: $2F{e}^{3+}\left(aq\right)+2SC{N}^{-}\left(aq\right)\rightleftharpoons 2FeSC{N}^{2+}\left(aq\right)$ is:

1. 280
2. 140
3. 19600
4. 70

Q. For the disproportionation reaction $2C{u}^{+}\left(aq\right)\rightleftharpoons Cu\left(s\right)+C{u}^{2+}\left(aq\right)$ at $298K,$ In K (where K is the equilibrium constant) is ____$\times {10}^{-1}$(Nearest integer).
Givrn: $(E_{C{u}^{2+}/C{u}^{+}}^o=0.16V;E_{C{u}^{+}/Cu}^o=0.52V;\frac{RT}{F}=0.025)$

Q. The equilibrium constant for the following reaction are given at $25{}^{\circ }C$
$2A\leftrightharpoons B+C,K_1=1.0$
$2B\leftrightharpoons C+D,K_2=16$
$2C+D\leftrightharpoons 2P,K_3=25$
The equilibrium constant for the reaction $P\leftrightharpoons A+\frac{1}{2}B$ at $25{}^{\circ }C$ is

1. $\frac{1}{20}$
2. $\frac{1}{42}$
3. $20$
4. $21$

Q. One mole of $N_2$ and 3 moles of $H_2$ are mixed in a litle flask. If $50\%N_2$ is converted into ammonia by the reaction, $N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$
then the total number of moles of gas at equilibrium is

1. 1.5
2. 3
3. 4.5
4. 6

Q. For the reaction: $2HI\left(g\right)\rightleftharpoons H_2\left(g\right)+I_2\left(g\right)$
The degree of dissociation of $HI$ (g) is related to equilibrium constant, $K_p$ by the expression

1. $\frac{1+2\sqrt{K_p}}{2}$
2. $\sqrt{\frac{1+2K_p}{2}}$
3. $\sqrt{\frac{2K_p}{1+2K_P}}$
4. $\frac{2\sqrt{K_p}}{1+2\sqrt{K_p}}$

Q. Determine the value of equilibrium constant $\left(K_c\right)$ for the reaction $A_{2\left(g\right)}+B_{2\left(g\right)}\leftrightharpoons 2A{B}_{\left(g\right)}$
If $10$ moles of $A_2,$ $15$ moles of $B_2$ and $5$ moles of $AB$ are placed in a $2\text{L}$ vessel and allowed to come to equilibrium. The final concentration of $AB$ is $7.5\text{M}$.

1. $4.5$
2. $1.5$
3. $3.0$
4. $6.0$

Q. $N{H}_{4}HS\left(s\right)\rightleftharpoons N{H}_3\left(g\right)+H_{2}S\left(g\right),$ If $K_p=64$ $at{m}^2$, equilibrium pressure of the mixture is?

1. 16 atm
2. 8 atm
3. 64 atm
4. None of the above

Q. For the reaction $A\left(g\right)+3B\left(g\right)\rightleftharpoons 2C\left(g\right)$ at ${27}^{o}C,$ 2 moles of A, 4 moles of B and 6 moles of C are present in 2 litre vessel. If $K_c$ for the reaction is 1.2, the reaction will proceed in:

1. Forward direction
2. Backward direction
3. The reaction will always be in equilibrium
4. none of these

Q. Consider the following gaseous equilibria with equilibrium constants $K_1$ and $K_2$ respectively.
$S{O}_2\left(g\right)+\frac{1}{2}{O}_2\left(g\right)\rightleftharpoons S{O}_3\left(g\right)2S{O}_3\left(g\right)\rightleftharpoons 2S{O}_2\left(g\right)+O_2\left(g\right)$
The equilibrium constants are related as :

1. 
2. 
3. 
4. 

Q. For the reaction, $N_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2NO\left(g\right)$, the equilibrium constant is $K_1$. The equilibrium constant is $K_2$ for $2NO\left(g\right)+O_2\left(g\right)\rightleftharpoons 2N{O}_2\left(g\right)$. What is K for the reaction $N{O}_2\left(g\right)\rightleftharpoons \frac{1}{2}{N}_2\left(g\right)+O_2\left(g\right)$?

1. 
2. 
3. 
4. 

Q.

For the following reaction, the equilibrium constant K_c at 298 K is 1.6 × 10¹⁷.

(${{\mathrm{Fe}}_{\left(\mathrm{aq}\right)}}^{2+}+{{\mathrm{S}}^{2-}}_{\left(\mathrm{aq}\right)}\rightleftharpoons \mathrm{FeS}\left(\mathrm{s}\right)$

When an equal volume of 0.06 M Fe⁺² and 0.2 M S^-2 solution are mixed, then the equilibrium concentration of Fe⁺² is found to be Y × 10^-17 M. Y is:

Q. Given the equilibrium constant values
$\left(I\right)N_2\left(g\right)+\frac{1}{2}{O}_2\left(g\right)\rightleftharpoons N_{2}O\left(g\right);K_C=2.7\times {10}^{-18}$
$\left(II\right)N_2{O}_4\left(g\right)\rightleftharpoons 2NO\left(g\right);K_C=4.6\times {10}^{-3}$
$\left(III\right)\frac{1}{2}{N}_2\left(g\right)+O_2\left(g\right)\rightleftharpoons N{O}_2\left(g\right)K_{C}4.1\times {10}^{-9}$
Thus for the reaction,
$2N_{2}O\left(g\right)+3O_2\left(g\right)\rightleftharpoons 2N_2{O}_4\left(g\right),K_C$ is

1. $5.46\times {10}^7$
2. $5.46\times {10}^{-7}$
3. $1.832\times {10}^{-6}$
4. $1.832\times {10}^6$

Q. The solubility product of $AgCl$ at ${25}^{\circ }C$ is $1\times {10}^{-10}$. A solution of $A{g}^{+}$ at a concentration of $4\times {10}^{-3}M$ just fails to yield a precipitate of $AgCl$ with a concentration of $1\times {10}^{-3}M$ of $C{l}^{-}$ when the concentration of $N{H}_3$ in the solution is $2\times {10}^{-2}M$. Calculate the equilibrium constant for
$\left[Ag\right(N{H}_3{)}_2{]}^{+}\rightleftharpoons A{g}^{+}+2N{H}_3$

1. ${10}^{-12}$
2. ${10}^{-10}$
3. ${10}^{-8}$
4. ${10}^{-2}$

Q. Consider the reaction
$N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$
Which of the following is correct, if the total pressure at which the equilibrium is established, is increased without changing the temperature?

1. $K$ will remain same
2. $K$ will decrease
3. $K$ will increase
4. $K$ will increase initially and decrease when pressure is very high

Q. At a certain temperature the equilibrium constant $K_c$ is 0.25 for the reaction $A_2\left(g\right)+B_2\left(g\right)\rightleftharpoons C_2\left(g\right)+D_2\left(g\right)$
If we take 1 mole of each of the four gases in a 10 litre container, what would be equilibrium concentration of $A_2\left(g\right).$

1. 0.13
2. 0.25
3. 1
4. 0

Q. The equilibrium constants for the following are:
$N_2+3H_2\rightleftharpoons 2N{H}_3{K}_1$
$N_2+O_2\rightleftharpoons 2NO{K}_2$
$H_2+\frac{1}{2}{O}_2\to H_{2}O{K}_3$
The equilibrium constant (K) of the reaction:
$2N{H}_3+\frac{5}{2}{O}_2\stackrel{K}{\rightleftharpoons }2NO+3H_{2}O,$ will be

1. $K_1{K}_3^3/K_2$
2. $K_2{K}_3^3/K_1$
3. $K_2{K}_3/K_1$
4. $K_2^3{K}_3/K_1$

Q.

A hypothetical reaction : $A_{\left(g\right)}+B_{\left(g\right)}\rightleftharpoons C_{\left(g\right)}+D_{\left(g\right)}$ occurs in a single step, the specific rate constant of forward reaction at TK is $2.0\times {10}^{-3}mo{l}^{-1}L{s}^{-1}$. When start is made with equimolar amounts of A and B, it is found that the concentration of A is twice that of C at equilibrium. The specific rate constant of the backward reaction is ?

1. $8.0\times {10}^{-3}mo{l}^{-1}L{s}^{-1}$

2. $1.5\times {10}^{2}mo{l}^{-1}L{s}^{-1}$

3. $Noneofthese$

4. $5.0\times {10}^{-4}mo{l}^{-1}L{s}^{-1}$

Q. Consider the following equilibrium in a closed container $N_2{O}_4\left(g\right)\rightleftharpoons 2N{O}_2\left(g\right)$. At a fixed temperature, the volume of the reaction container is halved. For this change, which of the following statements held true regarding the equilibrium constant $\left(K_P\right)$ and degree of dissociation $\left(\alpha \right)$:-

1. Neither $K_P$ nor $\alpha$ changes
2. Both $K_P$ and $\alpha$ changes
3. $K_P$ changes, but $\alpha$ does not change
4. $K_P$ does not change, but $\alpha$ changes

Q. For the given reaction, $2A\left(s\right)+B\left(g\right)\rightleftharpoons C\left(g\right)+2D\left(s\right)+E\left(s\right)$ the degree of dissociation of B was found to be 20% at 300 K and 24% at 500 K. The rate of backward reaction

1. increases with increase in pressure and temperature
2. increases with increase in pressure and decrease in temperature
3. depends on temperature only and decreases with increase in temperature
4. increases with increasing the concentration of B and increasing the temperature

Q. The equilibrium mixture for $2S{O}_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2S{O}_3\left(g\right)$ present in 1L vessel at ${600}^{o}C$ contains 0.50, 0.12, and 5.0 mole of $S{O}_2,O_2\text{and}S{O}_3$ respectively.
Calculate $K_C$ for the given change at ${600}^{o}C.$

1. $675.23mo{l}^{-1}L$
2. $765.32mo{l}^{-1}L$
3. $833.33mo{l}^{-1}L$
4. $801.23mo{l}^{-1}L$

Q. The equilibrium constant for,
$2H_{2}S\left(g\right)\rightleftharpoons 2H_2\left(g\right)+S_2\left(g\right)$
is 0.0118 at 1300 K while the heat of dissociation is 597.4 kJ. The standard equilibrium constant of the reaction at 1200 K is:

1. ${10}^{-4}$
2. ${10}^{-6}$
3. ${10}^{-8}$
4. ${10}^{-10}$

Q. The approach of the following equilibrium was observed kinetically from both directions
$PtC{l}_4^{2-}+H_{2}O\rightleftharpoons Pt\left(H_{2}O\right)C{l}_3^{-}+C{l}^{-}$
At 25°C, it is found $\frac{–d\left[PtC{l}_4^{2-}\right]}{dt}=(3.9\times {10}^{-5}{s}^{-1)})\left[PtC{l}_4^{2-}\right]-(2.1\times {10}^{-3}Lmo{l}^{-1}{s}^{-1})\left[Pt\right(H_{2}O\left)C{l}_3^{-}\right]\left[C{l}^{-}\right]$
Value of $K_C$ when fourth $C{l}^{-}$ is complexed in the reaction is:

1. $1.85\times {10}^{-2}$
2. $1.86\times 2$
3. $53.85$
4. $8.19\times {10}^{-8}$

Q. The equilibrium constants of the following are
$N_2+3H_2\rightleftharpoons 2N{H}_3;K_1$
$N_2+O_2\rightleftharpoons 2NO;K_2$

$H_2+\frac{1}{2}{O}_2\rightleftharpoons H_{2}O;K_3$
The equilibrium constant (K) of the reaction:
$2N{H}_3+\frac{5}{2}{O}_2\stackrel{K}{\rightleftharpoons }2NO+3H_{2}O$ will be

1. $K_2{K}_3^3/K_1$
2. $K_2{K}_3/K_1$
3. $K_2^3{K}_3/K_1$
4. $K_1{K}_3^3/K_2$

Q. If a mixture 0.4 mole $H_2$ and 0.2 mole $B{r}_2$ is heated at $700\text{K}$ at equilibrium, the value of equilibrium constant is $0.25\times {10}^{10}$ then find out the ratio of concentrations of $\left(B{r}_2\right)$ and $\left(HBr\right)$ (Report your answer as $\frac{B{r}_2}{HBr}\times {10}^{11}$)

1. 90
2. 100
3. 70
4. 80

Q.

When 3.06 g of solid $N{H}_4$HS is introduced into a two-litre evacuated flask at 27 ${}^{o}C$, 30$\%$ of the solid decomposes into gaseous ammonia and hydrogen sulphide. Choose the most appropriate one regarding $K_c$, $K_p$ and degree of dissociation $\alpha$:

1. , atm;

2. , ; is not defined

3. , ;

4. and are not defined. But

Q.

Consider the following equilibria at ${25}^{\circ }C,2N{O}_{\left(g\right)}\rightleftharpoons N_{2\left(g\right)}+O_{2\left(g\right)};K_1=4\times {10}^{30}andN{O}_{\left(g\right)}+\frac{1}{2}B{r}_{2\left(g\right)}\rightleftharpoons NOB{r}_{\left(g\right)};K_2=1.4mo{l}^{-\frac{1}{2}}{L}^{\frac{1}{2}}.$ The value of K_C for the reaction (at same temperature) $\frac{1}{2}{N}_{2\left(g\right)}+\frac{1}{2}{O}_{2\left(g\right)}+\frac{1}{2}B{r}_{2\left(g\right)}\rightleftharpoons NOB{r}_{\left(g\right)}$ is :

1. $3.5\times {10}^{-31}$

2. $2.8\times {10}^{15}$

3. $5.6\times {10}^{30}$

4. $7.0\times {10}^{-16}$

Q. In which one of the following reactants, $K_p$ is less than $K_c$?

1. $PC{l}_5\left(g\right)\rightleftharpoons PC{l}_3\left(g\right)+C{l}_2\left(g\right)$
2. $H_2\left(g\right)+I_2\left(g\right)\rightleftharpoons 2HI\left(g\right)$
3. $2S{O}_3\left(g\right)\rightleftharpoons 2S{O}_2\left(g\right)+O_2\left(g\right)$
4. $N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$

Q. The following equilibrium concentrations were measured at $800K:\left[S{O}_2\right]=3.0\times {10}^{-3}M;\left[O_2\right]=3.5\times {10}^{-3}M;\left[S{O}_3\right]=5.0\times {10}^{3}M$ Calculate the equilibrium constant at $800K$ for the chemical reaction in equilibrium for both directions.
$2S{O}_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2S{O}_3\left(g\right)$
($K_c$ is the equilibrium constant for the forward reaction and $K_c^{{}^{\prime }}$ is the equilibrium constant for the backward reaction)

1. $K_c=0.793\times {10}^3,K_c^{{}^{\prime }}=1.2\times {10}^{-3}$
2. $K_c=0.893\times {10}^3,K_c^{{}^{\prime }}=1.2\times {10}^{-3}$
3. $K_c=0.793\times {10}^3,K_c^{{}^{\prime }}=2.2\times {10}^{-3}$
4. $K_c=0.893\times {10}^3,K_c^{{}^{\prime }}=2.2\times {10}^{-3}$

Q. For the reaction, $N_2\left(g\right)+O_2\left(g\right)\leftrightharpoons 2NO\left(g\right)$, the value of $K_c$ at ${300}^{\circ }C$ is $0.1$. When the equilibrium concentrations of both the reactants is $0.5\text{mol}$, what is the value of $K_p$ at the same temperature?

1. $0.5$
2. $0.1$
3. $0.01$
4. $0.025$

Q.

For a chemical reaction, ${\mathrm{K}}_{\mathrm{eq}}\mathrm{is}100\mathrm{at}300\mathrm{K}$ , the value of Δ${\mathrm{G}}^{\mathrm{o}}\mathrm{is}–\mathrm{xR}\mathrm{Joule}\mathrm{at}1\mathrm{atm}\mathrm{pressure}$. Find the value of $\mathrm{x}$. (Use ln $10=2.3$)?