Mole Conversion Practice!! Avogadro’s Number, Molar Mass, Molar Volume Name: Date: Block: (a) How many atoms are in 2 molecules of Hg(IO3)2? (b) What volume at STP is occupied by 1.45 x 10 30 molecules of COF2 gas? (c) How many molecules are there in 64.0 g of FeS? (d) How many moles are in 25.0 mL of HCN at STP? (e) What volume at STP is occupied by 43.5 g of ClF3? (f) How many moles are in 2.75 x 10 23 atoms of Fe? (g) How many molecules are there in 125 mL of NOCl at STP?