Chapter 11, Problem 73A

Interpretation Introduction

Interpretation:

The use of mole ratio to calculate the limiting reagent needs to be explained.

Concept introduction:

Mole is defined as the $6.02214\times {10}^{23}$ particles of any substance.

Mole Ratio is the ratio of number of moles of product to the number of moles of reactant.

Explanation of Solution

Mole Ratio is the ratio of number of moles of product to the number of moles of reactant. This method commonly used for a reaction having two reactants or more than two reactants.

Let’s take an example to determine the limiting reagent.

$2A+3B\to C+2D$ and one mole of each reactant is provided.

First take the mole ratio with respect to each reactant

For reactant A

Divide the equation by 2

$\text{1}\text{mole}\text{of}\text{A}\text{produce=}\frac{\text{1}}{\text{2}}\text{moles}\text{of}\text{C}$

For reactant B

Divide the equation by 3

$\text{1}\text{mole}\text{of}\text{B}\text{produce=}\frac{\text{1}}{\text{3}}\text{moles}\text{of}\text{C}$

Now, one mole of each reactant is provided.

The reactant which produces least number of moles of product is the limiting reagent.

And for the above case reactant B is the limiting reagent.