Chapter 3: Problem 70
Oxygen masks for producing \(\mathrm{O}_{2}\) in emergency situations contain potassium superoxide, \(\mathrm{KO}_{2}\). It reacts with \(\mathrm{CO}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}\) in exhaled air to produce oxygen: $$ 4 \mathrm{KO}_{2}(s)+2 \mathrm{H}_{2} \mathrm{O}(g)+4 \mathrm{CO}_{2}(g) \longrightarrow 4 \mathrm{KHCO}_{3}(s)+3 \mathrm{O}_{2}(g) $$