Question

A gaseous mixture was prepared by taking equal moles of $CO$ and $N_2.$ If the total pressure of the mixture was found $1$ atmosphere, the partial pressure of the nitrogen $(N_2)$ in the mixture is

• A. 0.8 atm
• B. 0.9 atm
• C. 1 atm
• D. 0.5 atm

Answer 1

Answer: (D)

The partial pressure of gas $\propto$ Mole fraction of gas ( $X$ gas)
$X_{CO}=\frac{n_{CO}}{n_{CO}+n_{N_2}}=\frac{n_{CO}}{2n_{CO}}\left[\because n_{CO}=n_{N_2}\right]$
$\Rightarrow X_{CO}=\frac{1}{2}=0.5$
Partial pressure of $N_2=X_{N_2}\cdot P_T=\left[1-X_{CO}\right]\cdot P$
$=[1-0.5]\times [1]=0.5atm$