Chapter 7, Problem 6STP

Interpretation Introduction

Interpretation: The coefficient for iron in the balanced reaction of iron(II) oxide and carbon to form iron and carbon dioxide needs to be determined.

Concept Introduction: Chemical equation is written in such a way that the symbolic representation of reaction represents the reaction taking place in the system. The reactants are written on the left-hand side and the products are written on the right-hand side of the equation and are separated by an arrow, two or more reactants and products are separated by “+”.

The reactions for which the number of atoms of each element in the reactant and in the product, side are equal, such reactions are said to be a balanced chemical equation.

Answer to Problem 6STP

The correct option is (b): 2.

Explanation of Solution

The chemical formula of involved compounds and elements are:

  $\begin{array}{l}\text{Iron}\left(\text{II}\right)\text{ oxide: FeO}\\ \text{Carbon: C}\\ {\text{Carbon dioxide: CO}}_{\text{2}}\\ \text{Iron: Fe}\end{array}$

So, the chemical reaction of iron(II) oxide and carbon to form iron and carbon dioxide is:

  $\text{FeO + C }\to {\text{CO}}_{\text{2}}+\text{Fe}$

The reaction is not balanced as the number of O atoms in the reactant side is 1 and on the product side is 2. So, in order to balance the reaction, coefficient 2 is written before FeO on the reactant side and coefficient, 2 is written before Fe on the product side. So, the balanced chemical reaction is:

  $\text{2FeO + C }\to {\text{CO}}_{\text{2}}+2\text{Fe}$

Hence, the coefficient for iron in the balanced reaction of iron(II) oxide and carbon to form iron and carbon dioxide is 2.