Question

Most mixtures of hydrogen gas with oxygen gas are explosive. However, a mixture that contains less than 3.0 % O₂ is not. If enough O₂ is added to a cylinder of H₂ at 33.2 atm to bring the total pressure to 34.5 atm, is the mixture explosive?

Short answer

It is explosive because there is more than 3.0% O₂ in the combination.

Step-by-step solution

Definition of pressure 

A unit of pressure is defined as the force applied across a unit area.

Find contains in the mixture

Initial pressure = 33.2 atm, Total pressure = 34.5atm.

Pressure increased after adding:

\begin{aligned}{{\rm{O}}_2}=34.5\;{\rm{atm}}-33.2\;{\rm{atm}}\\=1.3\;{\rm{atm}}\end{aligned}

Partial pressure of O₂= 1.3 atm

Percentage ofO₂ added to increase the pressure

\[\frac{{1.3}}{{34.5}}\times 100=3.77\% \]

Therefore, because there is more than 3.0 % O₂ in the mixture, it is explosive.