Chapter 25, Problem 106A

Interpretation Introduction

Interpretation: The question is to balance the given chemical equations.

Concept Introduction: The inclusion of stoichiometric coefficients in the reactants and products is necessary to balance chemical equations. This is significant because a chemical equation must adhere to the laws of conservation of mass and constant proportions, meaning that both the reactant and product sides of the equation must include the same amount of atoms of each element.

Answer to Problem 106A

The balanced chemical reactions are:

  $\begin{array}{l}$ \text{Ca}{(\text{OH})}_2+2\text{HCl}\to {\text{CaCl}}_2+2{\text{H}}_2\text{O}${\text{Fe}}_2{\text{O}}_3+3{\text{H}}_2\to 2\text{Fe}+3{\text{H}}_2\text{O}\\ {\text{2NaHCO}}_3+{\text{H}}_2{\text{SO}}_4\to {\text{Na}}_2{\text{SO}}_4+2{\text{CO}}_2+2{\text{H}}_2\text{O}\\ {\text{2C}}_2{\text{H}}_6+7{\text{O}}_2\to 4{\text{CO}}_2+6{\text{H}}_2\text{O}\end{array}$

Explanation of Solution

Given information:

The unbalanced chemical equations given are:

  $\begin{array}{l}$ \text{a}.\text{Ca}{(\text{OH})}_2+\text{HCl}\to {\text{CaCl}}_2+{\text{H}}_2\text{O}$\text{b}{\text{.Fe}}_2{\text{O}}_3+{\text{H}}_2\to \text{Fe}+{\text{H}}_2\text{O}\\ \text{c}{\text{.NaHCO}}_3+{\text{H}}_2{\text{SO}}_4\to {\text{Na}}_2{\text{SO}}_4+{\text{CO}}_2+{\text{H}}_2\text{O}\\ \text{d}{\text{.C}}_2{\text{H}}_6+{\text{O}}_2\to {\text{CO}}_2+{\text{H}}_2\text{O}\end{array}$

Consider the first reaction,

  $\text{Ca}{(\text{OH})}_2+\text{HCl}\to {\text{CaCl}}_2+{\text{H}}_2\text{O}$

Balancing the chemical reaction by balancing the number of moles,

  $\text{Ca}{(\text{OH})}_2+2\text{HCl}\to {\text{CaCl}}_2+2{\text{H}}_2\text{O}$

Consider the second reaction,

  ${\text{Fe}}_2{\text{O}}_3+{\text{H}}_2\to \text{Fe}+{\text{H}}_2\text{O}$

Balancing the chemical reaction by balancing the number of moles,

  ${\text{Fe}}_2{\text{O}}_3+3{\text{H}}_2\to 2\text{Fe}+3{\text{H}}_2\text{O}$

Consider the second reaction,

  ${\text{NaHCO}}_3+{\text{H}}_2{\text{SO}}_4\to {\text{Na}}_2{\text{SO}}_4+{\text{CO}}_2+{\text{H}}_2\text{O}$

Balancing the chemical reaction by balancing the number of moles,

  ${\text{2NaHCO}}_3+{\text{H}}_2{\text{SO}}_4\to {\text{Na}}_2{\text{SO}}_4+2{\text{CO}}_2+2{\text{H}}_2\text{O}$

Consider the second reaction,

  ${\text{C}}_2{\text{H}}_6+{\text{O}}_2\to {\text{CO}}_2+{\text{H}}_2\text{O}$

Balancing the chemical reaction by balancing the number of moles,

  ${\text{2C}}_2{\text{H}}_6+7{\text{O}}_2\to 4{\text{CO}}_2+6{\text{H}}_2\text{O}$

Conclusion

Hence, the given chemical reactions are balanced above.