MCQ question on ideal gas law.?

Question

i need help on this MCQ question on ideal gas law.. i have tried for 30 mins but cant seem to work it out..Hope someone can help me . thanks alot

In an experiment, 0.30g of the volatile liquid Q formed 0.025 dm3 of vapour at 100C and at atmospheric pressure. What is the relative molecular mass of Q? [ Assume 1 mol of vapour occupies 22.4dm3 at s.t.p]
A. (0.025 X 273 X 22.4) divide by (0.30 X 373)
B.(0.025 X 373 X 22.4) divide by (0.30 by 273)
C. (0.30 X 273 X 22.4 ) divide by (0.025 X 373 )
D. (0.30 X 373 X 22.4) divide by (0.025 X 273)

My approach to this question was using pV=nRt, R and t were constant..thats why V1 divide by n1t1 = V2 divide by n2t2
But i dont know how to proceed further since i duno how to find V1

sorry for the mistake , its R and P constant thats y V1 divide by n1t1 = V2 divide by n2t2

Answer 1

First 1 use L instead of dm^3 (it is the same unit)

a mole of vapour is 22.4L at 0°C = 273K
at 100°C 1 mole occupies a volume of 22.4*373/273=30.605L
so 0.025L re present 0.025/30.605=8.169*10^-4mole=0.3g
and the molecular weight is 0.3/8.169*10^-4 =368g

the answer is D