In which one of the following equilibria, K p ≠ K c ?

N O 2 g + S O 2 g ⇌ N O g + S O 3 g

For the reaction: 2 NO 2 g ⇌ 2 NO g + O 2 g , K c = 1 .8 × 10 - 6 at 184 o C , R = 0 .0831 J / molK When K p and K c are compared at 184 o C. It is found that

Whether K p is greater than, less than or equal to K c depends upon the total gas pressure.

EASY

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The forward rate constant for the elementary reversible gaseous reaction

$C_{2} H_{6} ⇌ 2 {CH}_{3} is 1.57 \times 1 0^{- 3} s^{-1} at 100 K$

What is the rate constant for the backward reaction at this temperature if 10^-4moles of CH₃ and 10 moles of C₂H₆ are present in a 10 litre vessel at equilibrium.

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Important Questions on Equilibrium

HARD

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

20 litre

container at

400 K

contains

{CO}_{2} (g)

at pressure

0.4 atm

and an excess of

SrO

(neglect the volume of solid

SrO

). The volume of the container is now decreased by moving the movable piston fitted in the container. The maximum volume of the container, when the pressure of

{CO}_{2}

attains its maximum value, will be:

(Given that : {SrCO}_{3} (s) ⇌ SrO (s) + {CO}_{2} (g), K_{p} = 1 .6 atm)

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

$4.5$ moles each of hydrogen and iodine is heated in a sealed ten litre vessel.At equilibrium, $3$ moles of $HI$ were found. The equilibrium constant for $H_{2} (g) + I_{2} (g) ⇌ 2 {HI}_{(g)}$ is ........

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

For the non-stoichiometry reaction,

2 A + B \to C + D

, the following kinetic data were obtained in three separate experiments, all at

298 K

Initial Concentration (A)	Initial Concentration (B)	Initial rate of formation of C $({mol L}^{-} S^{-})$
$0.1 M$	$0.1 M$	$1.2 \times 1 0^{- 3}$
$0.1 M$	$0.2 M$	$1.2 \times 1 0^{- 3}$
$0.2 M$	$0.1 M$	$2.4 \times 1 0^{- 3}$

The rate law for the formation of

C

EASY

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

The value of $K_{c}$ for the reaction:

$A + 3 B ⇌ 2 C at 400 ° C$ is $0.5 mol L^{- 1} .$ Calculate the value of $K_{P}$ in $atm$ .

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

A sample of

HI (g)

is placed in a flask at a pressure of

0.2 atm .

At equilibrium, partial pressure of

HI (g)

0.04 atm .

What is

Kp

for the given equilibrium ?

2 HI (g) ⇌ H_{2} (g) + I_{2} (g)

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

In which one of the following equilibria,

K_{p} \neq K_{c} ?

HARD

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

What are the values of

\frac{K_{p}}{K_{c}}

for the following reactions at

300 K

respectively?

(At

300 K, RT = 24 .62 {dm}^{3} atm {mol}^{- 1}

)

N_{2} (g) + O_{2} (g) ⇌ 2 NO (g); \frac{K_{p}}{K_{c}} = x_{1}

N_{2} O_{4} (g) ⇌ 2 {NO}_{2} (g); \frac{K_{p}}{K_{c}} = x_{2}

N_{2} (g) + 3 H_{2} (g) ⇌ 2 {NH}_{3} (g); \frac{K_{p}}{K_{c}} = x_{3}

EASY

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

The relationship between

K_{p}

and

K_{c}

K_{p} = K_{c} {(RT)}^{Δn}

. What would be the value of

Δn

for the reaction,

{NH}_{4} Cl (s) ⇌ {NH}_{3} (g) + HCl (g)

EASY

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

Burning the coal is represented as

C_{(s)} + O_{2 (g)} ⟶ {CO}_{2 (g)} .

The rate of this reaction is increased by

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

For the reaction:

2 {NO}_{2 (g)} ⇌ 2 {NO}_{(g)} + O_{2 (g)},

(K_{c} = 1 .8 \times 10^{- 6} at 184^{o} C), (R = 0 .0831 J / molK)

When

K_{p}

and

K_{c}

are compared at

184^{o} C.

It is found that

EASY

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

For the given equilibrium reaction,

2 A (g) ⇌ 2 B (g) + C (g)

the equilibrium constant

(K_{c})

1000 K

4 \times 10^{- 4}

. Calculate

K_{p}

for the reaction at

800 K

temperature

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

The value of $K_{c} us 64 at 800 K$ for the reaction

$N_{2} (g) + 3 H_{2} (g) \to 2 {NH}_{3} (g)$

The value of $K_{c}$ for the following reaction is :

${NH}_{3} (g) \to \frac{1}{2} N_{2} (g) + \frac{3}{2} H_{2} (g)$

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

For a reaction

2 A_{(g)} ⇌ 2 B_{(g)} + C_{(g)}, K_{c} = 3.75 \times 10^{- 6}

1069 K

. The approximate value of

K_{p}

for this reaction at the same temperature is

(R = 0.082 L bar {mol}^{- 1} K^{- 1})

EASY

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

For the reaction

{SO}_{2} (g) + \frac{1}{2} O_{2} (g) ⇌ {SO}_{3} (g)

, if

K_{P} = K_{C} {(RT)}^{x}

where the symbols have usual meaning then the value of

x

is:
(assuming ideality)

EASY

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

The value of

K_{C}

for the equilibrium reaction:

{CO}_{2 (g)} + C_{(s)} ⇌ 2 {CO}_{(g)}

T (K)

0.036 .

If the equilibrium concentration of

{CO}_{2 (g)}

0.004 M,

the concentration of

{CO}_{(g)}

{molL}^{- 1}

EASY

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

Consider the following reversible chemical reactions:

A_{2} (g) + B_{2} (g) \overset{k_{1}}{⇌} 2 A B (g)

.....(1)

6 A B (g) \overset{k_{2}}{⇌} 3 A_{2} (g) + 3 B_{2} (g)

.....(2)

The relation between

K_{1}

and

K_{2}

is:

MEDIUM

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

In a chemical reaction,

A + 2 B \overset{K}{⇌} 2 C + D

, the initial concentration of

B

was

1.5

times of the concentration of

A

, but the equilibrium concentrations of

A

and

B

were found to be equal. The equilibrium constant

(K)

for the chemical reaction is:

EASY

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

For the reaction:

${SO}_{2 (g)} + \frac{1}{2} O_{2 (g)} \overset{}{⇌} {SO}_{3 (g)}$

$\frac{K_{P}}{K_{C}}$ is

HARD

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

The reaction

${CaCO}_{3} (s) ⇌ CaO (s) + {CO}_{2} (g)$

is in equilibrium in a closed vessel at $298 K .$ The partial pressure (in atm) of ${CO}_{2} (g)$ in the reaction vessel is closest to:

[Given: The change in Gibbs energies of formation at $298 K$ and $1$ bar for

$CaO (s) = - 603.501 kJ {mol}^{- 1}$

${CO}_{2} (g) = - 394.389 kJ {mol}^{- 1}$

${CaCO}_{3} (s) = - 1128.79 kJ {mol}^{- 1}$

Gas constant $R = 8.314 J K^{- 1} {mol}^{- 1}$ ]

EASY

Chemistry>Physical Chemistry>Equilibrium>Law of Chemical Equilibrium and Equilibrium Constants

The decay profiles of three radioactive species

A, B

and

C

are given below:

Question Image

These profiles imply that the decay constants

k_{A}, k_{B}

and

k_{C}

follow the order

The forward rate constant for the elementary reversible gaseous reaction C 2 H 6 ⇌ 2 CH 3 is 1 . 5 7 × 1 0 - 3 s -1 at 100 K What is the rate constant for the backward reaction at this temperature if 10-4 moles of CH3 and 10 moles of C2H6 are present in a 10 litre vessel at equilibrium.

Important Questions on Equilibrium

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