Henry's law states that
partial pressure of a gas in the vapour phase is proportional to the mole
fraction of the gas in the solution. If p is
the partial pressure of the gas in the vapour phase and x is
the mole fraction of the gas, then Henry's law can be expressed as:
p = KH x
Henry's law constant
Some important applications of Henry's law are mentioned below.
are sealed under high pressure to increase the solubility of CO2 in
soft drinks and soda water.
law states that the solubility of gases increases with an increase in pressure.
Therefore, when a scuba diver dives deep into the sea, the increased sea
pressure causes the nitrogen present in air to dissolve in his blood in great
amounts. As a result, when he comes back to the surface, the solubility of
nitrogen again decreases and the dissolved gas is released, leading to the
formation of nitrogen bubbles in the blood. This results in the blockage of
capillaries and leads to a medical condition known as 'bends' or 'decompression
Hence, the oxygen tanks used by scuba divers are filled with air and diluted
with helium to avoid bends.
concentration of oxygen is low in the blood and tissues of people living at high
altitudes such as climbers. This is because at high altitudes, partial pressure
of oxygen is less than that at ground level. Low-blood oxygen causes climbers to
become weak and disables them from thinking clearly. These are symptoms of