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?

PV=nRT
If half of the mass of hydrogen occupies 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.
V1=n1RT1/P1=30 mL
Again,
P2V2=n2RT2
So (1/9) × V = (n1/2) × R × 3T1
From 1 and 2 equation
V = 9 × 30 × 3 / 2 = 405 mL
Hence option C is correct.