Kp And Kc Relationship And Characteristics Of K MCQs

When a reaction reaches equilibrium, the forward and reverse reactions occur at the same rate, and the concentrations of the reactants and products remain constant as long as the system remains undisturbed. But what happens if this equilibrium is disrupted? In 1888, Henry Le Chatelier introduced the Le Chatelier principle, which states that if an external stress is applied to a system at equilibrium, the system will adjust to partially counteract that stress. Essentially, when a stress is applied to a chemical equilibrium, the equilibrium will shift in the direction that alleviates the applied stress.

What will be the value of Kp if the Kc is 26 for a reaction, PCl5 ⇌ PCl3 + Cl2 at 25°C?

(a) 0.57
(b) 0.46
(c) 0.83
(d) 0.61

If Kp and Kc are equilibrium constants in terms of partial pressure and concentration

(a) Kp = Kc/RT
(b) Kp = KcRT
(c) Kp = Kc/(RT)𐤃n
(d) Kp = Kc(RT)𐤃n

For which of the following reactions is Kp less than Kc?

(a) 2HI ⇌ H2 + I2
(b) N2 + O2 ⇌ 2NO
(c) N2O4 ⇌ 2NO2
(d) 2SO2 + O2 ⇌ 2SO3

For a reaction in equilibrium

(a) Q (concentration quotient) = K (equilibrium constant)
(b) Q > K
(c) Q < K
(d) none of the above

Active mass in the law of mass action is

(a) molar concentration
(b) absolute concentration
(c) concentration at 0°C
(d) molar mass

Two moles of PCl5 were heated to 400°C in a 2-liter closed vessel. At equilibrium, 40% of PCl5 was dissociated into PCl3 and Cl2. Its Kc will be

(a) 3.75 mol/L
(b) 0.533 mol/L
(c) 0.267 mol/L
(d) None of the above

Which of the following is an example of solid-solution equilibrium?

(a) dissolution of sugar in water
(b) melting of ice
(c) evaporation of water in a closed vessel
(d) none of the above

When Q (concentration quotient) is smaller than the equilibrium constant

(a) reaction will be in equilibrium
(b) reaction will proceed in the forward direction
(c) reaction will proceed in the backward direction
(d) none of the above

The mass of a gas dissolved in a given mass of a solvent at any temperature is directly proportional to

(a) pressure of gas
(b) volume of gas
(c) density of gas
(d) none of the above

Which of the following is not correct?

(a) large value of K indicates a large amount of products
(b) small value of K indicates a large amount of reactants
(c) for K < 1, the amount of reactants > the amount of products
(d) none of the above