Chapter U4.72, Problem 1TAI

Interpretation Introduction

Interpretation:

The balancing of atoms in a chemical equation must be explained.

Concept introduction:

A balanced chemical equation is the evidence of conservation of mass.

Answer to Problem 1TAI

Atoms in a chemical equation can be balanced by manually counting the number of each atom in both the side of chemical equation.

Explanation of Solution

As mass is conserved so in a chemical reaction more mass will not be created or no mass will be destroyed. To maintain this, total number of each atom must be same in reactant and product side of the chemical equation.

For example, the reaction of Fe and HCl is balanced in the following way:

  $Fe\left(s\right)+HCl\left(aq\right)\to FeC{l}_2+H_2$

In this reaction there is one Fe atom in both the side. But in right side there are two Cl and two H atoms. In left side, number of H and Cl atom is 1.

To make these equal, there must be 2 moles of HCl in the left side.

Thus, balanced chemical equation will be:

  $Fe\left(s\right)+2HCl\left(aq\right)\to FeC{l}_2+H_2$

In the balanced equation, the coefficients of Fe, HCl, FeCl₂ and H₂ are 1,2, 1 and 1 respectively.