State Henry's law and mention some important applications?
Henry's law This law states that 'the solubility of a gas in a liquid is directly proportional to the pressure of the gas.'
The partial pressure of the gas in vapour phase (p) is proportional to the mole fraction of the gas (x) in the solution'. it is expressed as
where, KH= Henry's law constant
p = Partial pressure of the gas in vapour phase
x = Mole fraction of the gas
Applications of Henry's law
1. To increase the solubility of CO2 in soda water and soft drinks, the bottle is sealed under high pressure.
2. To avoid the toxic effects of high concentration of nitrogen in the blood, the tanks used by scuba divers are filled with air diluted with helium (11.7% helium, 56.2% nitrogen and 32.1% oxygen).
3. At high altitudes, the partial pressure of oxygen is less than that at the ground level because the atmospheric pressure is less. Low blood oxygen causes anoxia.