Chapter 20, Problem 32QAP

Interpretation Introduction

Interpretation:

The mass of KO₂ that is left after the water in exhaled air reacts with it should be calculated.

Concept introduction:

The moles of any compound or element can be calculated by given formula:

$n=\frac{m}{M}$

Where n is number of moles, m is the given mass and M is molar mass.

To obtain the volume of gases, the ideal gas equation is used as:

$PV=nRT$

Where P is pressure, T is temperature, n is number of moles, R is gas constant, and V is volume of gas.

Actually, in breathing apparatus the exhaled air contains carbon dioxide and water.

The KO₂ first reacts with water to form potassium hydroxide which later removes carbon dioxide by forming KHCO₃.

The reactions are as follows:

$\begin{array}{l}{\text{(1) 4KO}}_{\text{2}}{\text{+2H}}_{\text{2}}\text{O}\to {\text{4KOH+3O}}_{\text{2}}\\ \text{(2) }\text{}{\text{KOH+CO}}_{\text{2}}\to {\text{KHCO}}_{\text{3}}\end{array}$