Number of moles= Volume at STP / Molar volume at STP (litres) Molar volume of any gas at stp is 22.4 L Rearrange the equation and substitute the values.
No. Of moles x 22.4 = volume (liters)
A) 1 x 22.4 = 22.4 liters B) 2 x 22.4 = 44.8 L C) 4.5 x 22.4 = 100.8 L