Question

Which of the following is true for the rate law of a reversible reaction?

(a) It reduces to irreversible form when product concentration is zero

(b) It satisfies thermodynamic relationships at all times

(c) Rate law can be written only in terms of partial pressures

(d) Rate law can be written only in terms of concentrations

I got this question during an internship interview.

I'd like to ask this question from Reversible Reactions Rate Laws topic in portion Rate Laws and Stoichiometry of Chemical Reaction Engineering

Answer 1

Right option is (a) It reduces to irreversible form when product concentration is zero

Easy explanation: Rate law can be written in terms of both concentrations or partial pressures. The thermodynamic relationships are satisfied only at equilibrium. If the product concentration is zero, the rate of the backward reaction becomes zero and the rate law reduces to irreversible form.