Question

A quantity of hydrogen gas occupies a volume of 30.0 mL at a certain temperature and pressure. What volume would half this mass of hydrogen occupy at triple the absolute temperature if the pressure were one ninth that of the original gas?

• A. 270 mL
• B. 90 mL
• C. 405 mL
• D. 137 mL

Answer 1

The correct option is C 405 mL

$PV=nRT$
If half of the mass of hydrogen occupy at triple the absolute temperature if the pressure were one-ninth the original gas,

Here initial no. of moles is half of the final no. of moles because molar mass is same both the time.

$V_1=\frac{n_{1}R{T}_1}{P_1}=30ml$ ----- 1

Again,

$P_2{V}_2=n_{2}R{T}_2$

So $\frac{p_1}{9}\times V=\frac{n_1}{2}\times R\times 3T_1$ ---- 2

From 1 and 2 equation

$V=\frac{9\times 30\times 3}{2}=405mL$

Hence option C is correct.