1.35C: Understand How to Carry Out Calculations Involving Gas Volumes and the Molar Volume of a Gas ( 24 dm3 and 24 000 cm3 at Room Temperature and Pressure (rtp))

CALCULATIONS INVOLVING GASES

GENERAL EQUATION:

1.  CALCULATING VOLUME

s

EQUATION:

Volume of Gas ( dm3 )      =      Amount of Gas ( Mol )     x    24     OR              Volume of Gas ( cm3 )      =      Amount of Gas ( Mol )     x    24000

s

Example:

s

NAME OF GAS	AMOUNT OF GAS	VOLUME OF GAS
HYDROGEN	3 Mol	( 3 x 24 ) = 72 dm3
CARBON DIOXIDE	0.25 Mol	( 0.25 x 24 ) = 6 dm3
OXYGEN	5.4 Mol	( 5.4 x 24000 ) = 129600 cm3
AMMONIA	0.02 Mol	( 0.02 x 24 ) = 0.48 dm3

    2.  CALCULATING MOLES

EQUATION:

s

s

Example:

s

NAME OF GAS	VOLUME OF GAS	MOLES OF GAS
METHANE	225.6 dm3	( 225.6 ÷ 24 ) = 9.4 mol
CARBON MONOXIDE	7.2 dm3	( 7.2 ÷ 24 ) = 0.3 mol
SULFUR DIOXIDE	960 dm3	( 960 ÷ 24 ) = 40 mol
OXYGEN	1200 cm3	( 1200 ÷ 24000 ) = 0.05 mol