2 grams of Helium diffuses from a porous plate in 4min. How many grams of CH4 would diffuse through the same plate in same time under similar conditions?

For different gases of different masses diffused Grahams Law :mt∝Mm= mass of the gas diffusedt = time taken for diffusionM =gram molecular weight of gasmHetHe×tCH4mCH4=MHeMCH424×4mCH4=416=12mCH4=4g ; Alternate method : At constant T and P, WHeWCH4=MHeMCH4 ; 2x=416; x=4 g ;