Quiz - chemistry - Chemical Equilibrium-PYQ

Q1. In liquid-gas equilibrium, the pressure of vapours above the liquid is constant at Source: orcusprep.in

NEET 1995

easy

constant temperature

low temperature

high temperature

none of these.

Q2. The equilibrium constants of the following are:

$$ \text{N}_2 + 3\text{H}_2 \rightleftharpoons 2\text{NH}_3; K_1 $$
$$ \text{N}_2 + \text{O}_2 \rightleftharpoons 2\text{NO}; K_2 $$
$$ \text{H}_2 + \tfrac{1}{2}\text{O}_2 \rightleftharpoons \text{H}_2\text{O}; K_3 $$

The equilibrium constant (K) of the reaction:

$$ 2\text{NH}_3 + \tfrac{5}{2}\text{O}_2 \rightleftharpoons 2\text{NO} + 3\text{H}_2\text{O} $$

will be Source: orcusprep.in

NEET 2017, 2007, 2003

hard

$K_2K_3^3/K_1$

$K_2K_3/K_1$

$K_2^3K_3/K_1$

$K_1K_3^3/K_2$

Q3. If the equilibrium constant for $ \text{N}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{NO}(g) $ is $K$, the equilibrium constant for $ \tfrac{1}{2} \text{N}_2(g) + \tfrac{1}{2} \text{O}_2(g) \rightleftharpoons \text{NO}(g) $ will be Source: orcusprep.in

NEET 2015

easy

$ \tfrac{1}{2}K $

$ K $

$ K^2 $

$ K^{1/2} $

Q4. Given that the equilibrium constant for the reaction, $ 2\text{SO}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{SO}_3(g) $ has a value of 278 at a particular temperature. What is the value of the equilibrium constant for the following reaction at the same temperature?

$ \text{SO}_3(g) \rightleftharpoons \text{SO}_2(g) + \tfrac{1}{2}\text{O}_2(g) $ Source: orcusprep.in

NEET Mains 2012

medium

1.8 x 10-3

3.6 x 10-3

6.0 x 10-2

1.3 x 10-5

Q5. Given the reaction between 2 gases represented by A2 and B2 to give the compound AB(g).

A2(g) + B2(g) $ \rightleftharpoons $ 2AB(g)

At equilibrium, the concentration of A2 = 3.0 x 10-3 M, of B2 = 4.2 x 10-3 M, of AB = 2.8 x 10-3 M. If the reaction takes place in a sealed vessel at 527°C, then the value of Kc will be Source: orcusprep.in

NEET Mains 2012

medium

2.0

1.9

0.62

4.5

Q6. For the reaction, N2(g) + O2(g) $ \rightleftharpoons $ 2NO(g), the equilibrium constant is K1. The equilibrium constant is K2 for the reaction, 2NO(g) + O2(g) $ \rightleftharpoons $ 2NO2(g). What is K for the reaction, NO2(g) $ \rightleftharpoons $ 1/2N2(g) + O2(g)? Source: orcusprep.in

NEET 2011

hard

$ \frac{1}{2}K_1K_2 $

$ \frac{1}{4}K_1K_2 $

$ \left( \frac{1}{K_1K_2} \right)^{1/2} $

$ \frac{1}{K_1K_2} $

Q7. The dissociation constants for acetic acid and HCN at 25°C are 1.5 x 10-5 and 4.5 x 10-10 respectively. The equilibrium constant for the equilibrium, CN– + CH3COOH $ \rightleftharpoons $ HCN + CH3COO– would be Source: orcusprep.in

NEET 2009

medium

3.0 x 10-5

3.0 x 10-4

3.0 x 104

3.0 x 105

Q8. The value of equilibrium constant of the reaction, HI(g) $ \rightleftharpoons $ 1/2H2(g) + 1/2I2(g) is 8.0. The equilibrium constant of the reaction H2(g) + I2(g) $ \rightleftharpoons $ 2HI(g) will be Source: orcusprep.in

NEET 2008

medium

16

1/8

1/16

1/64

Q9. Equilibrium constants K1 and K2 for the following equilibria:

$$ \text{NO}(g) + \tfrac{1}{2}\text{O}_2(g) \rightleftharpoons \text{NO}_2(g); K_1 $$
$$ 2\text{NO}_2(g) \rightleftharpoons 2\text{NO}(g) + \text{O}_2(g); K_2 $$

are related as Source: orcusprep.in

NEET 2005

easy

$K_2 = 1/K_1^2$

$K_2 = K_1^2$

$K_2 = 1/K_1$

$K_2 = K_1/2$

Q10. If K1 and K2 are the respective equilibrium constants for the two reactions,

$$ \text{XeF}_6(g) + \text{H}_2\text{O}(g) \rightarrow \text{XeOF}_4(g) + 2\text{HF}(g) \; (K_1) $$
$$ \text{XeO}_4(g) + \text{XeF}_6(g) \rightarrow \text{XeOF}_4(g) + \text{XeO}_3\text{F}_2(g) \; (K_2) $$

the equilibrium constant of the reaction,

$$ \text{XeO}_4(g) + 2\text{HF}(g) \rightarrow \text{XeO}_3\text{F}_2(g) + \text{H}_2\text{O}(g) $$

, will be Source: orcusprep.in

NEET 1998

hard

$K_1/K_2$

$K_1 \cdot K_2$

$K_1/(K_2)^2$

$K_2/K_1$

Q11. The equilibrium constant for the reaction N2 + 3H2 $ \rightleftharpoons $ 2NH3 is K, then the equilibrium constant for the equilibrium 2NH3 $ \rightleftharpoons $ N2 + 3H2 is Source: orcusprep.in

NEET 1996

easy

K

1/K

1/2K

Q12. K1 and K2 are equilibrium constants for reactions (i) and (ii) respectively.

(i) $ \text{N}_2(g) + \text{O}_2(g) \rightleftharpoons 2\text{NO}(g) $
(ii) $ \text{NO}(g) \rightleftharpoons \tfrac{1}{2}\text{N}_2(g) + \tfrac{1}{2}\text{O}_2(g) $

Source: orcusprep.in

NEET 1989

easy

$ K_1 = (1/K_2)^2 $

$ K_1 = K_2^2 $

$ K_1 = K_2 $

$ K_1 = (K_2)^0 $

Q13. The reaction, 2A(g) + B(g) $ \rightleftharpoons $ 3C(g) + D(g) is begun with the concentrations of A and B both at an initial value of 1.00 M. When equilibrium is reached, the concentration of D is measured and found to be 0.25 M. The value for the equilibrium constant for this reaction is given by the expression Source: orcusprep.in

NEET Mains 2010

hard

[(0.75)3(0.25)] \div [(1.00)2(1.00)]

[(0.75)3(0.25)] \div [(0.50)2(0.75)]

[(0.75)3(0.25)] \div [(0.50)2(0.25)]

[(0.75)3(0.25)] \div [(0.75)2(0.25)]

Q14. The values of Kp1 and Kp2 for the reactions, X $ \rightleftharpoons $ Y + Z ...(i) A $ \rightleftharpoons $ 2B ...(ii) are in the ratio 9 : 1. If degree of dissociation of X and A be equal, then total pressure at equilibrium (i) and (ii) are in the ratio Source: orcusprep.in

NEET 2008

medium

36 : 1

1 : 1

3 : 1

1 : 9

Q15. A 20 litre container at 400 K contains CO2(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 pressure of CO2 attains its maximum value, will be

(Given that : SrCO3(s) $ \rightleftharpoons $ SrO(s) + CO2(g), Kp = 1.6 atm) Source: orcusprep.in

NEET 2017

hard

10 litre

4 litre

2 litre

5 litre

Q16. In which of the following equilibrium Kc and Kp are not equal? Source: orcusprep.in

NEET 2010

easy

2NO(g) $ \rightleftharpoons $ N2(g) + O2(g)

SO2(g) + NO2(g) $ \rightleftharpoons $ SO3(g) + NO(g)

H2(g) + I2(g) $ \rightleftharpoons $ 2HI(g)

2C(s) + O2(g) $ \rightleftharpoons $ 2CO2(g)

Q17. If the concentration of OH– ions in the reaction Fe(OH)3(s) $ \rightleftharpoons $ Fe3+(aq) + 3OH–(aq) is decreased by 1/4 times, then equilibrium concentration of Fe3+ will increase by Source: orcusprep.in

NEET 2008

medium

64 times

4 times

8 times

16 times.

Q18. Equilibrium constant Kp for following reaction

MgCO3(s) $ \rightleftharpoons $ MgO(s) + CO2(g) Source: orcusprep.in

NEET 2000

easy

Kp = pCO2

Kp = pCO2 x pMgO / pMgCO3

Kp = pCO2 + pMgO / pMgCO3

Kp = pMgCO3 / (pCO2 x pMgO)

Q19. The dissociation equilibrium of a gas AB2 can be represented as : 2AB2(g) $ \rightleftharpoons $ 2AB(g) + B2(g). The degree of dissociation is x and is small compared to 1. The expression relating the degree of dissociation (x) with equilibrium constant Kp and total pressure P is Source: orcusprep.in

NEET 2008

hard

$(2Kp/P)^{1/2}$

$(Kp/P)$

$(2Kp/P)$

$(2Kp/P)^{1/3}$

Q20. If the value of equilibrium constant for a particular reaction is 1.6 x 1012, then at equilibrium the system will contain Source: orcusprep.in

NEET 2015, Cancelled

easy

mostly products

similar amounts of reactants and products

all reactants

mostly reactants.

Q21. In Haber process, 30 litres of dihydrogen and 30 litres of dinitrogen were taken for reaction which yielded only 50% of the expected product. What will be the composition of gaseous mixture under the aforesaid condition in the end? Source: orcusprep.in

NEET 2003

hard

20 litres ammonia, 20 litres nitrogen, 20 litres hydrogen

10 litres ammonia, 25 litres nitrogen, 15 litres hydrogen

20 litres ammonia, 10 litres nitrogen, 30 litres hydrogen

20 litres ammonia, 25 litres nitrogen, 15 litres hydrogen

Q22. The reaction quotient (Q) for the reaction N2(g) + 3H2(g) $ \rightleftharpoons $ 2NH3(g) is given by $ Q = [NH_3]^2 / ([N_2][H_2]^3) $. The reaction will proceed from right to left if Source: orcusprep.in

NEET 2003

easy

Q = Kc

Q < Kc

Q > Kc

Q = 0

Q23. Hydrolysis of sucrose is given by the following reaction : Sucrose + H2O $ \rightleftharpoons $ Glucose + Fructose. If the equilibrium constant (Kc) is 2 x 1013 at 300 K, the value of $ \Delta_rG^\circ $ at the same temperature will be Source: orcusprep.in

NEET 2020

medium

$ -8.314 \text{ J mol}^{-1}\text{K}^{-1} x 300 \text{ K} x \ln(2 x 10^{13}) $

$ 8.314 \text{ J mol}^{-1}\text{K}^{-1} x 300 \text{ K} x \ln(2 x 10^{13}) $

$ 8.314 \text{ J mol}^{-1}\text{K}^{-1} x 300 \text{ K} x \ln(3 x 10^{13}) $

$ -8.314 \text{ J mol}^{-1}\text{K}^{-1} x 300 \text{ K} x \ln(4 x 10^{13}) $

Q24. Which of the following statements is correct for a reversible process in a state of equilibrium? Source: orcusprep.in

NEET 2015, Cancelled

easy

$ \Delta G^\circ = -2.30 \text{ RT} \log K $

$ \Delta G^\circ = 2.30 \text{ RT} \log K $

$ \Delta G = -2.30 \text{ RT} \log K $

$ \Delta G = 2.30 \text{ RT} \log K $

Q25. Match List I (Equations) with List II (Type of processes) and select the correct option.

List I (Equations)	List II (Type of processes)
A. Kp > Q	(i) Non- spontaneous
B. $ \Delta G^\circ < RT \ln Q $	(ii) Equilibrium
C. Kp = Q	(iii) Spontaneous and endothermic
D. T > $ \Delta H / \Delta S $	(iv) Spontaneous

Source: orcusprep.in

NEET Mains 2010

hard

A - (i), B - (ii), C - (iii), D - (iv)

A - (iii), B - (iv), C - (ii), D - (i)

A - (iv), B - (i), C - (ii), D - (iii)

A - (ii), B - (i), C - (iv), D - (iii)

Q26. Which one of the following conditions will favour maximum formation of the product in the reaction A2(g) + B2(g) $ \rightleftharpoons $ X2(g), $ \Delta_rH = -X \text{ kJ} $? Source: orcusprep.in

NEET 2018

easy

Low temperature and high pressure

Low temperature and low pressure

High temperature and high pressure

High temperature and low pressure

Q27. For the reversible reaction, N2(g) + 3H2(g) $ \rightleftharpoons $ 2NH3(g) + heat. The equilibrium shifts in forward direction Source: orcusprep.in

NEET 2014

easy

by increasing the concentration of NH3(g)

by decreasing the pressure

by decreasing the concentrations of N2(g) and H2(g)

by increasing pressure and decreasing temperature.

Q28. For a given exothermic reaction, Kp and K'p are the equilibrium constants at temperatures T1 and T2, respectively. Assuming that heat of reaction is constant in temperature range between T1 and T2, it is readily observed that Source: orcusprep.in

NEET 2014

medium

Kp > K'p

Kp < K'p

Kp = K'p

Kp / K'p = 1

Q29. KMnO4 can be prepared from K2MnO4 as per the reaction, 3MnO42– + 2H2O $ \rightleftharpoons $ 2MnO4– + MnO2 + 4OH–. The reaction can go to completion by removing OH– ions by adding Source: orcusprep.in

NEET 2013

medium

CO2

SO2

HCl

KOH

Q30. The value of $ \Delta H $ for the reaction X2(g) + 4Y2(g) $ \rightleftharpoons $ 2XY4(g) is less than zero. Formation of XY4(g) will be favoured at Source: orcusprep.in

NEET 2011

easy

high temperature and high pressure

low pressure and low temperature

high temperature and low pressure

high pressure and low temperature.

Q31. For the reaction : CH4(g) + 2O2(g) $ \rightleftharpoons $ CO2(g) + 2H2O(l), $ \Delta_r H = -170.8 \text{ kJ mol}^{-1} $. Which of the following statements is not true? Source: orcusprep.in

NEET 2006

medium

The reaction is exothermic.

At equilibrium, the concentrations of CO2(g) and H2O(l) are not equal.

The equilibrium constant for the reaction is given by $ K_p = [\text{CO}_2] / ([\text{CH}_4][\text{O}_2]^2) $.

Addition of CH4(g) or O2(g) at equilibrium will cause a shift to the right.

Q32. Reaction BaO2(s) $ \rightleftharpoons $ BaO(s) + O2(g); $ \Delta H = +\text{ve} $. In equilibrium condition, pressure of O2 depends on Source: orcusprep.in

NEET 2002

easy

increase mass of BaO2

increase mass of BaO

increase temperature on equilibrium

increase mass of BaO2 and BaO both.

Q33. For any reversible reaction, if we increase concentration of the reactants, then effect on equilibrium constant Source: orcusprep.in

NEET 2000

easy

depends on amount of concentration

unchange

decrease

increase.

Q34. According to Le Chatelier’s principle, adding heat to a solid and liquid in equilibrium will cause the Source: orcusprep.in

NEET 1993

easy

temperature to increase

temperature to decrease

amount of liquid to decrease

amount of solid to decrease.

Q35. Which one of the following information can be obtained on the basis of Le Chatelier principle? Source: orcusprep.in

NEET 1992

easy

Dissociation constant of a weak acid

Entropy change in a reaction

Equilibrium constant of a chemical reaction

Shift in equilibrium position on changing value of a constraint

Q36. The equilibrium concentration of the species in the reaction: A + B ⇌ C + D are 2, 3, 10, and 6 mol L⁻¹, respectively, at 300 K. Calculate ΔG⁰ for the reaction. (Given: R = 2 cal/mol K)

NEET 2023

hard

–13.73 cal

1372.60 cal

–137.26 cal

–1381.80 cal

Q37. For the reaction in equilibrium: N₂(g) + 3 H₂(g) ⇌ 2 NH₃(g), ΔH = −Q. The reaction is favored in the forward direction by:

NEET 2024

medium

Use of catalyst

Decreasing concentration of N₂

Low pressure, high temperature, and high concentration of ammonia

High pressure, low temperature, and higher concentration of H₂

Q38. At a given temperature and pressure, the equilibrium constant value for the equilibria are given below: 3 A₂ + B₂ ⇌ 2 A₃B, K₁; A₃B ⇌ 3/2 A₂ + 1/2 B₂, K₂. The relation between K₁ and K₂ is:

NEET 2024

hard

K₁² = 2K₂

K₂ = K₁ / 2

K₁ = 1 / √K₂

K₂ = 1 / √K₁

Q39. For the equilibrium: 2 NOCl(g) ⇌ 2 NO(g) + Cl₂(g) The value of the equilibrium constant is 3.0 × 10⁻⁶ at 1000 K. Find K_p for the reaction at this temperature (Given R = 8.314 J K⁻¹ mol⁻¹).

NEET 2024

hard

1.493

2.494 × 10⁻²

3.0 × 10⁻⁶

2.494 × 10⁻⁴

Q40. Consider the reaction in equilibrium: PCl₅ ⇌ PCl₃ + Cl₂ At 500 K, the concentration of PCl₅ = 1.40 M, concentration of Cl₂ = 1.60 M, and concentration of PCl₃ = 1.60 M. Calculate K_c.

NEET 2024

medium

2.00

2.6

1.83

3.4

Q41. Consider the following reaction in a sealed vessel at equilibrium with concentrations of N₂ = 3.0 × 10⁻³ M, O₂ = 4.2 × 10⁻³ M and NO = 2.8 × 10⁻³ M. 2NO(g) ⇌ N₂(g) + O₂(g) If 0.1 mol L⁻¹ of NO(g) is taken in a closed vessel, what will be degree of dissociation (α) of NO(g) at equilibrium?

NEET 2024

hard

0.00889

0.0889

0.8889

0.717

Q42. For the reaction 2A ⇌ B + C, K_c = 4 × 10⁻³. At a given time, the composition of reaction mixture is: [A] = [B] = [C] = 2 × 10⁻³ M. Then, which of the following is correct?

NEET 2024

medium

Reaction is at equilibrium

Reaction has a tendency to go in forward direction

Reaction has a tendency to go in backward direction

Reaction has gone to completion in forward direction

Q43. Higher yield of NO in N₂(g) + O₂(g) ⇌ 2NO(g) can be obtained at [ΔH of the reaction = +180.7 kJ mol⁻¹]

NEET 2025

medium

B, C, D only

A, C, D only

A, D only

B, C only

Q44. For the reaction A(g) ⇌ 2B(g), the backward reaction rate constant is higher than the forward reaction rate constant by a factor of 2500 at 1000 K. K_p for the reaction at 1000 K is. [Given: R = 0.0831 L atm mol⁻¹ K⁻¹]

NEET 2025

hard

0.033

0.021

83.1

2.077 × 10⁵

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Chemistry - Chemical Equilibrium-PYQ

List I (Equations)	List II (Type of processes)
A. Kp > Q	(i) Non- spontaneous
B. \( \Delta G^\circ < RT \ln Q \)	(ii) Equilibrium
C. Kp = Q	(iii) Spontaneous and endothermic
D. T > \( \Delta H / \Delta S \)	(iv) Spontaneous

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Chemistry - Chemical Equilibrium-PYQ

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