Question

The vapours of phosphine gas at ${27}^{\circ }\text{C}$ and 3 bar pressure has a density of:

• A. $4.09{\text{g mL}}^{-1}$
• B. $4.14{\text{g L}}^{-1}$
• C. $4.14{\text{kg L}}^{-1}$
• D. $2.04{\text{g L}}^{-1}$

Answer 1

The correct option is B $4.14{\text{g L}}^{-1}$

Given:
Pressure, $P=3\text{bar}=3\text{atm}$
Temperature, $T=300K$
Molar mass of Phosphine $P{H}_3$ gas, $M=34\text{g}$
$d=\frac{PM}{RT}=\frac{3\times 34}{0.0821\times 300}=4.14{\text{g L}}^{-1}$