Chapter 7.3, Problem 5RQ

Interpretation Introduction

Interpretation :

While balancing a chemical reaction which substance one should start with and why must be explained. The given chemical reaction must also be balanced

Concept Introduction :

Balancing a chemical reaction means keeping equal number of each atoms in both the sides.

Answer to Problem 5RQ

While balancing a chemical reaction one should start with the main reactant in which maximum types of different atoms are there.

The balanced equation is given below.

  ${\text{C}}_{\text{2}}{\text{H}}_{\text{5}}{\text{OH(l)+3O}}_{\text{2}}\text{(g)}\to {\text{2CO}}_{\text{2}}{\text{(g)+3H}}_{\text{2}}\text{O(g)}\text{.}$

Explanation of Solution

In this example ethyl alcohol (C₂H₅OH) is the starting material which is undergoing combustion reaction with oxygen. Ethanol contains all the types of atoms which are C, H and O.

To make the C and H equal in both the sides, 2 moles of CO₂ and 3 moles of H₂O are added in the right side. Finally to balance oxygen 3 moles O₂ is added in the left side.