Chemical Equilibrium · Chemistry · JEE Main

The equilibrium constant for decomposition of $\text{H}_2\text{O(g)}$

$ \text{H}_2\text{O(g)} \rightleftharpoons \text{H}_2\text{(g)} + \frac{1}{2}\text{O}_2\text{(g)} \quad (\Delta G^\circ = 92.34 \, \text{kJ mol}^{-1}) $

is $8.0 \times 10^{-3}$ at 2300 K and total pressure at equilibrium is 1 bar. Under this condition, the degree of dissociation ($\alpha$) of water is _________ $\times 10^{-2}$ (nearest integer value).

[Assume $\alpha$ is negligible with respect to 1]

Consider the following equilibrium,

$$\mathrm{CO}(\mathrm{~g})+2 \mathrm{H}_2(\mathrm{~g}) \rightleftharpoons \mathrm{CH}_3 \mathrm{OH}(\mathrm{~g})$$

0.1 mol of CO along with a catalyst is present in a $2 \mathrm{dm}^3$ flask maintained at 500 K . Hydrogen is introduced into the flask until the pressure is 5 bar and 0.04 mol of $\mathrm{CH}_3 \mathrm{OH}$ is formed. The $K_p^\theta$ is __________ $\times 10^{-3}$ (nearest integer).

Given : $\mathrm{R}=0.08 \mathrm{~dm}^3$ bar $\mathrm{K}^{-1} \mathrm{~mol}^{-1}$

Assume only methanol is formed as the product and the system follows ideal gas behaviour.

$37.8 \mathrm{~g} \mathrm{~N}_2 \mathrm{O}_5$ was taken in a 1 L reaction vessel and allowed to undergo the following reaction at 500 K

$$2 \mathrm{~N}_2 \mathrm{O}_{5(\mathrm{~g})} \rightleftharpoons 2 \mathrm{~N}_2 \mathrm{O}_{4(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}$$

The total pressure at equilibrium was found to be 18.65 bar.

Then, $\mathrm{Kp}=$ _________ $\times 10^{-2}$ [nearest integer]

Assume $\mathrm{N}_2 \mathrm{O}_5$ to behave ideally under these conditions.

Given: $\mathrm{R}=0.082$ bar $\mathrm{L} \mathrm{mol}^{-1} \mathrm{~K}^{-1}$

The following concentrations were observed at $$500 \mathrm{~K}$$ for the formation of $$\mathrm{NH}_3$$ from $$\mathrm{N}_2$$ and $$\mathrm{H}_2$$. At equilibrium ; $$\left[\mathrm{N}_2\right]=2 \times 10^{-2} \mathrm{M},\left[\mathrm{H}_2\right]=3 \times 10^{-2} \mathrm{M}$$ and $$\left[\mathrm{NH}_3\right]=1.5 \times 10^{-2} \mathrm{M}$$. Equilibrium constant for the reaction is ________.

For the reaction $$\mathrm{N}_2 \mathrm{O}_{4(\mathrm{~g})} \rightleftarrows 2 \mathrm{NO}_{2(\mathrm{~g})}, \mathrm{K}_{\mathrm{p}}=0.492 \mathrm{~atm}$$ at $$300 \mathrm{~K} . \mathrm{K}_{\mathrm{c}}$$ for the reaction at same temperature is _________ $$\times 10^{-2}$$.

(Given : $$\mathrm{R}=0.082 \mathrm{~L} \mathrm{~atm} \mathrm{~mol}^{-1} \mathrm{~K}^{-1}$$)

4.5 moles each of hydrogen and iodine is heated in a sealed ten litre vessel. At equilibrium, 3 moles of $$\mathrm{HI}$$ were found. The equilibrium constant for $$\mathrm{H}_{2}(\mathrm{~g})+\mathrm{I}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{HI}(\mathrm{g})$$ is _________.

A mixture of 1 mole of $$\mathrm{H}_{2} \mathrm{O}$$ and 1 mole of $$\mathrm{CO}$$ is taken in a 10 litre container and heated to $$725 \mathrm{~K}$$. At equilibrium $$40 \%$$ of water by mass reacts with carbon monoxide according to the equation :

$$\mathrm{CO}(\mathrm{g})+\mathrm{H}_{2} \mathrm{O}(\mathrm{g}) \rightleftharpoons \mathrm{CO}_{2}(\mathrm{~g})+\mathrm{H}_{2}(\mathrm{~g})$$.

The equilibrium constant $$\mathrm{K}_{\mathrm{c}} \times 10^{2}$$ for the reaction is ____________. (Nearest integer)

$$\mathrm{A}(g) \rightleftharpoons 2 \mathrm{~B}(g)+\mathrm{C}(g)$$

For the given reaction, if the initial pressure is $$450 \mathrm{~mm} ~\mathrm{Hg}$$ and the pressure at time $$\mathrm{t}$$ is $$720 \mathrm{~mm} ~\mathrm{Hg}$$ at a constant temperature $$\mathrm{T}$$ and constant volume $$\mathrm{V}$$. The fraction of $$\mathrm{A}(\mathrm{g})$$ decomposed under these conditions is $$x \times 10^{-1}$$. The value of $$x$$ is ___________ (nearest integer)

The number of correct statement/s involving equilibria in physical processes from the following is ________

(A) Equilibrium is possible only in a closed system at a given temperature.

(B) Both the opposing processes occur at the same rate.

(C) When equilibrium is attained at a given temperature, the value of all its parameters became equal.

(D) For dissolution of solids in liquids, the solubility is constant at a given temperature.

The equilibrium composition for the reaction $$\mathrm{PCl}_{3}+\mathrm{Cl}_{2} \rightleftharpoons \mathrm{PCl}_{5}$$ at $$298 \mathrm{~K}$$ is given below:

$$\left[\mathrm{PCl}_{3}\right]_{\mathrm{eq}}=0.2 \mathrm{~mol} \mathrm{~L}^{-1},\left[\mathrm{Cl}_{2}\right]_{\mathrm{eq}}=0.1 \mathrm{~mol} \mathrm{~L}^{-1},\left[\mathrm{PCl}_{5}\right]_{\mathrm{eq}}=0.40 \mathrm{~mol} \mathrm{~L}^{-1}$$

If $$0.2 \mathrm{~mol}$$ of $$\mathrm{Cl}_{2}$$ is added at the same temperature, the equilibrium concentrations of $$\mathrm{PCl}_{5}$$ is __________ $$\times 10^{-2} \mathrm{~mol} \mathrm{~L}^{-1}$$

Given : $$\mathrm{K}_{\mathrm{c}}$$ for the reaction at $$298 \mathrm{~K}$$ is 20

(i) $$\mathrm{X}(\mathrm{g}) \rightleftharpoons \mathrm{Y}(\mathrm{g})+\mathrm{Z}(\mathrm{g}) \quad \mathrm{K}_{\mathrm{p} 1}=3$$

(ii) $$\mathrm{A}(\mathrm{g}) \rightleftharpoons 2 \mathrm{~B}(\mathrm{g}) \quad \mathrm{K}_{\mathrm{p} 2}=1$$

If the degree of dissociation and initial concentration of both the reactants $$\mathrm{X}(\mathrm{g})$$ and $$\mathrm{A}(\mathrm{g})$$ are equal, then the ratio of the total pressure at equilibrium $$\left(\frac{p_{1}}{p_{2}}\right)$$ is equal to $$\mathrm{x}: 1$$. The value of $$\mathrm{x}$$ is _____________ (Nearest integer)

For reaction : $$\mathrm{SO}_{2}(\mathrm{~g})+\frac{1}{2} \mathrm{O}_{2}(\mathrm{~g}) \rightleftharpoons \mathrm{SO}_{3}(\mathrm{~g})$$

$$\mathrm{K}_{\mathrm{p}}=2 \times 10^{12}$$ at $$27^{\circ} \mathrm{C}$$ and $$1 \mathrm{~atm}$$ pressure. The $$\mathrm{K}_{\mathrm{c}}$$ for the same reaction is ____________ $$\times 10^{13}$$. (Nearest integer)

(Given $$\mathrm{R}=0.082 \mathrm{~L} \mathrm{~atm} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$)

At 298 K

$$\mathrm{N_2~(g)+3H_2~(g)\rightleftharpoons~2NH_3~(g),~K_1=4\times10^5}$$

$$\mathrm{N_2~(g)+O_2~(g)\rightleftharpoons~2NO~(g),~K_2=1.6\times10^{12}}$$

$$\mathrm{H_2~(g)+\frac{1}{2}O_2~(g)\rightleftharpoons~H_2O~(g),~K_3=1.0\times10^{-13}}$$

Based on above equilibria, then equilibrium constant of the reaction, $$\mathrm{2NH_3(g)+\frac{5}{2}O_2~(g)\rightleftharpoons~2NO~(g)+3H_2O~(g)}$$ is ____________ $$\times10^{-33}$$ (Nearest integer).

Water decomposes at 2300 K

$$\mathrm{H_2O(g)\to H_2(g)+\frac{1}{2}O_2(g)}$$

The percent of water decomposing at 2300 K and 1 bar is ___________ (Nearest integer).

Equilibrium constant for the reaction is $$2\times10^{-3}$$ at 2300 K.

Consider the following reaction approaching equilibrium at 27$$^\circ$$C and 1 atm pressure

$$\mathrm{A+B}$$ $$\mathrel{\mathop{\kern0pt\rightleftharpoons} \limits_{{k_r} = {{10}^2}}^{{k_f} = {{10}^3}}} $$ $$\mathrm{C+D}$$

The standard Gibb's energy change $$\mathrm{(\Delta_r G^\theta)}$$ at 27$$^\circ$$C is ($$-$$) ___________ kJ mol$$^{-1}$$ (Nearest integer).

(Given : $$\mathrm{R=8.3~J~K^{-1}~mol^{-1}}$$ and $$\mathrm{\ln 10=2.3}$$)

At $$600 \mathrm{~K}, 2 \mathrm{~mol}$$ of $$\mathrm{NO}$$ are mixed with $$1 \mathrm{~mol}$$ of $$\mathrm{O}_{2}$$.

$$2 \mathrm{NO}_{(\mathrm{g})}+\mathrm{O}_{2}(\mathrm{g}) \rightleftarrows 2 \mathrm{NO}_{2}(\mathrm{g})$$

The reaction occurring as above comes to equilibrium under a total pressure of 1 atm. Analysis of the system shows that $$0.6 \mathrm{~mol}$$ of oxygen are present at equilibrium. The equilibrium constant for the reaction is ________. (Nearest integer)

At $$298 \mathrm{~K}$$, the equilibrium constant is $$2 \times 10^{15}$$ for the reaction :

$$\mathrm{Cu}(\mathrm{s})+2 \mathrm{Ag}^{+}(\mathrm{aq}) \rightleftharpoons \mathrm{Cu}^{2+}(\mathrm{aq})+2 \mathrm{Ag}(\mathrm{s})$$

The equilibrium constant for the reaction

$$ \frac{1}{2} \mathrm{Cu}^{2+}(\mathrm{aq})+\mathrm{Ag}(\mathrm{s}) \rightleftharpoons \frac{1}{2} \mathrm{Cu}(\mathrm{s})+\mathrm{Ag}^{+}(\mathrm{aq}) $$

is $$x \times 10^{-8}$$. The value of $$x$$ is _____________. (Nearest Integer)

A box contains 0.90 g of liquid water in equilibrium with water vapour at 27$$^\circ$$C. The equilibrium vapour pressure of water at 27$$^\circ$$C is 32.0 Torr. When the volume of the box is increased, some of the liquid water evaporates to maintain the equilibrium pressure. If all the liquid water evaporates, then the volume of the box must be __________ litre. [nearest integer]

(Given : R = 0.082 L atm K^$$-$$1 mol^$$-$$1)

(Ignore the volume of the liquid water and assume water vapours behave as an ideal gas.)

2NOCl(g) $$\rightleftharpoons$$ 2NO(g) + Cl₂(g)

In an experiment, 2.0 moles of NOCl was placed in a one-litre flask and the concentration of NO after equilibrium established, was found to be 0.4 mol/L. The equilibrium constant at 30$$^\circ$$C is ______________ $$\times$$ 10^$$-$$4.

40% of HI undergoes decomposition to H₂ and I₂ at 300 K. $$\Delta$$G$$^\Theta $$ for this decomposition reaction at one atmosphere pressure is __________ J mol^$$-$$1. [nearest integer]

(Use R = 8.31 J K^$$-$$1 mol^$$-$$1 ; log 2 = 0.3010, ln 10 = 2.3, log 3 = 0.477)

The standard free energy change ($$\Delta$$G$$^\circ$$) for 50% dissociation of N₂O₄ into NO₂ at 27$$^\circ$$C and 1 atm pressure is $$-$$ x J mol^$$-$$1. The value of x is ___________. (Nearest Integer)

[Given : R = 8.31 J K^$$-$$1 mol^$$-$$1, log 1.33 = 0.1239 ln 10 = 2.3]

PCl₅ dissociates as

PCl₅(g) $$\rightleftharpoons$$ PCl₃(g) + Cl₂(g)

5 moles of PCl₅ are placed in a 200 litre vessel which contains 2 moles of N₂ and is maintained at 600 K. The equilibrium pressure is 2.46 atm. The equilibrium constant K_p for the dissociation of PCl₅ is __________ $$\times$$ 10^$$-$$3. (nearest integer)

(Given : R = 0.082 L atm K^$$-$$1 mol^$$-$$1; Assume ideal gas behaviour)

2O₃(g) $$\rightleftharpoons$$ 3O₂(g)

At 300 K, ozone is fifty percent dissociated. The standard free energy change at this temperature and 1 atm pressure is ($$-$$) ____________ J mol^$$-$$1. (Nearest integer)

[Given : ln 1.35 = 0.3 and R = 8.3 J K^$$-$$1 mol^$$-$$1]

Given below are two statements :

Statement I : A catalyst cannot alter the equilibrium constant $\left(\mathrm{K}_{\mathrm{c}}\right)$ of the reaction, temperature remaining constant.

Statement II : A homogenous catalyst can change the equilibrium composition of a system, temperature remaining constant.

In the light of the above statements, choose the correct answer from the options given below

Consider the following chemical equilibrium of the gas phase reaction at a constant temperature : $\mathrm{A}(\mathrm{g}) \rightleftharpoons \mathrm{B}(\mathrm{g})+\mathrm{C}(\mathrm{g})$

If $p$ being the total pressure, $K_p$ is the pressure equilibrium constant and $\alpha$ is the degree of dissociation, then which of the following is true at equilibrium?

Consider the equilibrium

$$ \mathrm{CO}(\mathrm{g})+3 \mathrm{H}_2(\mathrm{~g}) \rightleftharpoons \mathrm{CH}_4(\mathrm{~g})+\mathrm{H}_2 \mathrm{O}(\mathrm{~g}) $$

If the pressure applied over the system increases by two fold at constant temperature then

(A) Concentration of reactants and products increases.

(B) Equilibrium will shift in forward direction.

(C) Equilibrium constant increases since concentration of products increases.

(D) Equilibrium constant remains unchanged as concentration of reactants and products remain same.

Choose the correct answer from the options given below :

At temperature T, compound $AB_{2(g)}$ dissociates as $AB_{2(g)} \rightleftharpoons AB_{(g)} + \frac{1}{2} B_{2(g)}$ having degree of dissociation $ x $ (small compared to unity). The correct expression for $ x $ in terms of $ K_p $ and $ p $ is:

For the reaction,

$$\mathrm{H}_2(\mathrm{~g})+\mathrm{I}_2(\mathrm{~g}) \rightleftharpoons 2 \mathrm{HI}(\mathrm{~g})$$

Attainment of equilibrium is predicted correctly by :

Consider the reaction

$$\mathrm{X}_2 \mathrm{Y}(\mathrm{~g}) \rightleftharpoons \mathrm{X}_2(\mathrm{~g})+\frac{1}{2} \mathrm{Y}_2(\mathrm{~g})$$

The equation representing correct relationship between the degree of dissociation (x) of $\mathrm{X}_2 \mathrm{Y}(\mathrm{g})$ with its equilibrium constant Kp is __________.

Assume $x$ to be very very small.

A vessel at 1000 K contains $\mathrm{CO}_2$ with a pressure of 0.5 atm . Some of $\mathrm{CO}_2$ is converted into CO on addition of graphite. If total pressure at equilibrium is 0.8 atm , then K_p is :

For the given hypothetical reactions, the equilibrium constants are as follows :

$$\begin{aligned} & \mathrm{X} \rightleftharpoons \mathrm{Y} ; \mathrm{K}_1=1.0 \\ & \mathrm{Y} \rightleftharpoons \mathrm{Z} ; \mathrm{K}_2=2.0 \\ & \mathrm{Z} \rightleftharpoons \mathrm{W} ; \mathrm{K}_3=4.0 \end{aligned}$$

The equilibrium constant for the reaction $$\mathrm{X} \rightleftharpoons \mathrm{W}$$ is

The ratio $$\frac{K_P}{K_C}$$ for the reaction :

$$\mathrm{CO}_{(\mathrm{g})}+\frac{1}{2} \mathrm{O}_{2(\mathrm{~g})} \rightleftharpoons \mathrm{CO}_{2(\mathrm{~g})}$$ is :

At $$-20^{\circ} \mathrm{C}$$ and $$1 \mathrm{~atm}$$ pressure, a cylinder is filled with equal number of $$\mathrm{H}_2, \mathrm{I}_2$$ and $$\mathrm{HI}$$ molecules for the reaction $$\mathrm{H}_2(\mathrm{~g})+\mathrm{I}_2(\mathrm{~g}) \rightleftharpoons 2 \mathrm{HI}(\mathrm{g})$$, the $$\mathrm{K}_{\mathrm{p}}$$ for the process is $$x \times 10^{-1}$$.

$$\mathrm{x}=$$ __________.

[Given : $$\mathrm{R}=0.082 \mathrm{~L} \mathrm{~atm} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$$]

Given below are two statements :

Statement I : On passing $$\mathrm{HCl}_{(\mathrm{g})}$$ through a saturated solution of $$\mathrm{BaCl}_2$$, at room temperature white turbidity appears.

Statement II : When $$\mathrm{HCl}$$ gas is passed through a saturated solution of $$\mathrm{NaCl}$$, sodium chloride is precipitated due to common ion effect.

In the light of the above statements, choose the most appropriate answer from the options given below :

The following reaction occurs in the Blast furnance where iron ore is reduced to iron metal

$$\mathrm{Fe}_2 \mathrm{O}_{3(s)}+3 \mathrm{CO}_{(g)} \rightleftharpoons \mathrm{Fe}_{(\mathrm{l})}+3 \mathrm{CO}_{2(g)}$$

Using the Le-chatelier's principle, predict which one of the following will not disturb the equilibrium.

The equilibrium constant for the reaction

$$\mathrm{SO}_3(\mathrm{~g}) \rightleftharpoons \mathrm{SO}_2(\mathrm{~g})+\frac{1}{2} \mathrm{O}_2(\mathrm{~g})$$

is $$\mathrm{K}_{\mathrm{c}}=4.9 \times 10^{-2}$$. The value of $$\mathrm{K}_{\mathrm{c}}$$ for the reaction given below is $$2 \mathrm{SO}_2(\mathrm{~g})+\mathrm{O}_2(\mathrm{~g}) \rightleftharpoons 2 \mathrm{SO}_3(\mathrm{~g})$$ is :

$$\mathrm{A}_{(\mathrm{g})} \rightleftharpoons \mathrm{B}_{(\mathrm{g})}+\frac{\mathrm{C}}{2}(\mathrm{g})$$ The correct relationship between $$\mathrm{K}_{\mathrm{P}}, \alpha$$ and equilibrium pressure $$\mathrm{P}$$ is

For the given reaction, choose the correct expression of $$\mathrm{K}_{\mathrm{C}}$$ from the following :-

$$\mathrm{Fe}_{(\mathrm{aq})}^{3+}+\mathrm{SCN}_{(\mathrm{aq})}^{-} \rightleftharpoons(\mathrm{FeSCN})_{(\mathrm{aq})}^{2+}$$

For a concentrated solution of a weak electrolyte ($$\mathrm{K}_{\text {eq }}=$$ equilibrium constant) $$\mathrm{A}_{2} \mathrm{B}_{3}$$ of concentration '$$c$$', the degree of dissociation '$$\alpha$$' is :

The equilibrium constant for the reversible reaction

2A(g) $$\rightleftharpoons$$ 2B(g) + C(g) is K₁

$${3 \over 2}$$A(g) $$\rightleftharpoons$$ $${3 \over 2}$$B(g) + $${3 \over 4}$$C(g) is K₂.

K₁ and K₂ are related as :

4.0 moles of argon and 5.0 moles of PCl₅ are introduced into an evacuated flask of 100 litre capacity at 610 K. The system is allowed to equilibrate. At equilibrium, the total pressure of mixture was found to be 6.0 atm. The K_p for the reaction is :

[Given : R = 0.082 L atm K^$$-$$1 mol^$$-$$1]

For a reaction at equilibrium

A(g) $$\rightleftharpoons$$ B(g) + $${1 \over 2}$$ C(g)

the relation between dissociation constant (K), degree of dissociation ($$\alpha$$) and equilibrium pressure (p) is given by :

The effect of addition of helium gas to the following reaction in equilibrium state, is :

$$\mathrm{PCl}_{5}(\mathrm{g}) \rightleftharpoons \mathrm{PCl}_{3}(\mathrm{g})+\mathrm{Cl}_{2}(\mathrm{g})$$