The number of moles =MolarmassMass
The number of molecules =moles×NA
One mole of any gas occupies 22.7L at STP.
(A) Moles of CH4=1616=1
Molecules =6.02×1023
Electrons =10×6.02×1023
=60.2×1023
(B) Moles of H2=21=0.5 mole
Volume at STP =21×22.7=11.35lit .
(C) 1 mole N2=28gm
(D) 0.5 mole SO2=21×64=32gm