Question

Which of the following is the correct expression for the rate of a reaction?

(a) \(\frac{Moles \, of \, product \, formed}{Volume \, of \, fluid×Time} \)

(b) \(\frac{Moles \, of \, reactant \, initially \, taken}{Volume \, of \, fluid×Time} \)

(c) \(\frac{Moles \, unreacted}{Volume \, of \, fluid×Time} \)

(d) \(\frac{Moles \, of \, product \, formed}{Volume \, of \, fluid} \)

The question was asked in an international level competition.

This is a very interesting question from Reaction Rates in section Basic Concepts of Chemical Reaction Engineering

Answer 1

Correct choice is (a) \(\frac{Moles \, of \, product \, formed}{Volume \, of \, fluid×Time} \)

Explanation: Rate of the reaction is the number of moles of the reactant component disappearing per unit volume per unit time. The moles of the product formed are the number of moles of the reactant species disappearing during the course of reaction.