2. Solubility of gases in pure iron

2.1 Henry's Law

In 1803, English physician and chemist William Henry demonstrated experimentally that the solubility of a gas in a solvent is proportional to its pressure. This law must be treated with caution, as it is based on three assumptions:

• the gas is perfect;

• the gas-metal solution is ideal;

• the molecularity of the solute in both dissolved and gaseous phases is the same.

Henry's Law assumes that dissolution is based on the mechanism: