Chapter 11.2, Problem 12PP

(a)

Interpretation Introduction

Interpretation:

A chemical equation for the reaction of sulfur dioxide with oxygen and water has to be balanced.

Concept introduction:

The substances that undergo chemical reaction are defined as reactants and the substances thus formed are known as products.

Answer to Problem 12PP

The balanced chemical equation is shown below:

${\text{2SO}}_2+2{\text{H}}_{\text{2}}\text{O}+{\text{O}}_{\text{2}}\to 2{\text{H}}_{\text{2}}{\text{SO}}_4$

Explanation of Solution

The reaction of sulfur dioxide with water and oxygen to produce sulfuric acid is shown below:

${\text{SO}}_2+{\text{H}}_{\text{2}}\text{O}+{\text{O}}_{\text{2}}\to {\text{H}}_{\text{2}}{\text{SO}}_4$

The coefficient of two is multiplied with sulfur dioxide, water, and sulfuric acid to balance the chemical equation as shown below:

${\text{2SO}}_2+2{\text{H}}_{\text{2}}\text{O}+{\text{O}}_{\text{2}}\to 2{\text{H}}_{\text{2}}{\text{SO}}_4$

(b)

Interpretation Introduction

Interpretation:

The $\text{12}\text{.5}\text{mol}$ of ${\text{SO}}_2$ is used to produce sulfuric acid. The number of moles of sulfuric acid produced is to be calculated.

Concept introduction:

According to law of conservation of mass it is not possible to form the mass or to destroy the mass. The mass always remains conserved.

The number of moles is calculated as shown below:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ (1)

Answer to Problem 12PP

The number of moles of sulfuric acid produced is $12.5\text{mol}$

Explanation of Solution

The balanced chemical equation is shown below:

${\text{2SO}}_2+2{\text{H}}_{\text{2}}\text{O}+{\text{O}}_{\text{2}}\to 2{\text{H}}_{\text{2}}{\text{SO}}_4$

The above equation shows that two moles of sulfuric acid reacts with two moles of water and one mole of oxygen to form two moles of sulfuric acid.

Therefore, the number of moles of sulfuric acid produced is,

$\begin{array}{c}2\text{mol}\text{of}{\text{SO}}_2=\text{2}\text{mol}\text{of}{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\\ 1\text{mol}\text{of}{\text{SO}}_2=\frac{\text{2}}{2}\text{mol}\text{of}{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\\ 12.5\text{mol}\text{of}{\text{SO}}_2=\frac{\text{2}}{2}\times 12.5\text{mol}\text{of}{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\\ =12.5\text{mol}\text{of}{\text{H}}_{\text{2}}{\text{SO}}_{\text{4}}\end{array}$

(c)

Interpretation Introduction

Interpretation:

The number of moles of oxygen needed is to be calculated.

Concept introduction:

According to law of conservation of mass it is not possible to form the mass or to destroy the mass. The mass always remains conserved.

Answer to Problem 12PP

The number of moles of oxygen needed is $6.25\text{mol}$

Explanation of Solution

The balanced chemical equation is shown below:

${\text{2SO}}_2+2{\text{H}}_{\text{2}}\text{O}+{\text{O}}_{\text{2}}\to 2{\text{H}}_{\text{2}}{\text{SO}}_4$

The above equation shows that two moles of sulfuric acid reacts with two moles of water and one mole of oxygen to form two moles of sulfuric acid.

Therefore, the number of moles of oxygen needed for $12.5\text{mol}$ of ${\text{SO}}_{\text{2}}$ is,

$\begin{array}{c}2\text{mol}\text{of}{\text{SO}}_2=1\text{mol}\text{of}{\text{O}}_2\\ 1\text{mol}\text{of}{\text{SO}}_2=\frac{1}{2}\text{mol}\text{of}{\text{O}}_2\\ 12.5\text{mol}\text{of}{\text{SO}}_2=\frac{1}{2}\times 12.5\text{mol}\text{of}{\text{O}}_2\\ =6.25\text{mol}\text{of}{\text{O}}_2\end{array}$