Question

Density of a gas is found to be $5.46g/d{m}^3$ at ${27}^{\circ }C$ and $2bar$ pressure. What will be its density at STP?

• A. $3.0gd{m}^{-3}$
• B. $5.0gd{m}^{-3}$
• C. $6.0gd{m}^{-3}$
• D. $10.82gd{m}^{-3}$

Answer 1

The correct option is A $3.0gd{m}^{-3}$

$P=\frac{n}{V}RT=\frac{m}{V}\times \frac{RT}{M}=\frac{dRT}{M}$

or $d=\frac{PM}{RT}$ or $d\propto \frac{P}{T}$

$\frac{d_1}{d_2}=\frac{P_1}{P_2}\times \frac{T_2}{T_1}$ or

$d_2=\frac{d_1\times P_2\times T_1}{P_1\times T_2}$

$d_2=\frac{5.46\times 1\times 300}{2\times 273}=3.0gd{m}^{-3}$

Therefore, the correct option is A.