Relationship Between No. Of Moles Of Gas With Volume

CHAPTER 3 : CHEMICAL FORMULAE & EQUATIONS

3.4 The Mole & the Volume of Gas

3.4 The Mole & the Volume of Gas

MOLAR VOLUME - volume occupied by 1 mole of any gas

22.4 dm3 at STP (0°C and 1 atm)

24 dm3 at Room Conditions (25°C and 1 atm)

3.4 The Mole & the Volume of Gas

In STP

O2 gas

Volume of O2 = 22.4 dm 3

In Room Condition

O2 gas

Volume of O2 = 24 dm 3

3.4 The Mole & the Volume of Gas

GENERALISATION OF MOLAR VOLUME OF GASES •1 mole of any gas always occupies the same volume under the same temperature and pressure.

3.4 The Mole & the Volume of Gas

RELATIONSHIP BETWEEN THE NUMBER OF MOLES AND THE MASS OF A SUBSTANCE

x molar volume

Volume of gas (dm3)

No. of Moles molar volume

Examples: Calculate the volume of 0.075 mol of carbon dioxide gas measured at STP

Try to find: Find the number of moles of 4800 cm³of ammonia gas at room conditions

3.4 The Mole & the Volume of Gas

No. of Particles

x NA NA

No. of Moles

molar x volume

x molar mass

molar volume

molar mass

Mass (g)

Volume of gas (dm3) P/S:Number of moles act as an intermediate

No. of particles

No. of moles

No. of moles

=

=

=

No. of moles x NA Mass (g) Molar mass (Ar or Mr) Volume (dm3) Molar volume

(STP=22.4 dm3 mol-1 or Room=24 dm3 mol1 )