Volume percentage
- Volume percentage can be defined as the ratio of Volume of the component of the solution and total mass of the solution multiplied by 100%.
- Mathematically,
Volume% of a component = 
- Volume percentage of ethanol in a 100 mL solution containing 10 mL of ethanol dissolved in water is 10%.
Mass % of ethanol = 
At this concentration the antifreeze lowers the freezing point of water to 255.4K or –17.6°C.
Problem:
Ami took a 20 cm3 mixture of CO, CH4 and He gases and exploded it by an electric discharge at room temperature with excess of oxygen. The volume initially contracted to 13.0 cm3. Then it further contracted to 14.0 cm3 when the residual gas is treated with KOH solution. Find out the consumption of gaseous mixture in terms of volume percentage.
Solution:
Take V1= Partial volumes of CO
V2= Partial volumes of CH4
V3 = Partial volumes of He
V1+V2+V3 = 20.0 cm3
The equation for combustion is as follows:
CO + ½ O2 --> CO2
CH4 + 2O2 --> CO2 + 2H2O
V1 volume of CO = ½ V1 volume of O2 = V1 volume of CO2
V2 volume of CH4 = 2V2 volume O2 = V2 volume of CO2
V1/2 + 2V2 = 13.0 cm3
Treating of residual gases with KOH solution would cause the absorption of CO2
V1+ V2 = 14.0 cm3
V1 = 10 cm3
V2 = 4.0 cm3
V3 = 6.0 cm3
Volume % of CO = 10/20 x 100 = 50
Volume % of CH4 = 4/20 X 100 = 20
Volume % of He = 100 - (50 + 20) = 30
