Q. 8.58 - An Introduction to General, Organic, and Biological Chemistry

Question

A gas mixture containing oxygen, nitrogen, and neon exerts a total pressure of $1.20 atm$. If helium added to the mixture increases the pressure to $1.50 atm$, what is the partial pressure, in atmospheres, of the helium?

Step-by-Step Solution

Answer

The partial pressure of helium is $0.3 atm$

Step 1: Given Information

We need to find the the partial pressure of helium.

Step 2: Simplify

In a gas, mixture, each gas exerts its partial pressure, which is the pressure it would exert if it were the gas in the container. Dalton's law that the total pressure of a gas mixture is the sum of the partial pressures of the gases in the mixture.  

Total pressure $P_{total }=1.5 atm$

$P_o+P_N+P_{Ne}=1.2 atm$

$$\begin{gathered} P_{total}=P_o+P_{He}+P_N+P_{Ne} \\ {P}_{He}=P_{total}-P_N-P_o -P_{Ne} \\ =1.5 atm -1.2 atm =0.3 atm \end{gathered}$$