Question

8.2 L of an ideal gas weighs 9.0 g at 300 K and 1 atm. pressure. The molecular mass of gas is

• A. 9
• B. 27
• C. 54
• D. 81

Answer 1

Answer: (B)

27

Answer 2

Apply $n = \frac{PV}{RT}$ or $\frac{9}{M} = \frac{PV}{RT}$ $\frac{1 \times 8.2}{0.082 \times 300} = \frac{9}{M}$ or M = $\frac{9}{1/3}$ = 27