Henry's law
Henry's law states that the
mass of a
gas that dissolves in a definite volume of liquid is directly proportional to the pressure of the gas provided the gas does not react with the solvent. William Henry formulated the formula in
1801.
A formula for Henry's Law is:
where
P is the partial pressure of the gaseous solute above the solution,
C is the concentration of the gas in
mol/
L and
k is the Henry's Law constant, which has the units L*atm/mol.
Taking the natural logarithm of the formula, gives us the more commonly used formula:
This version is used to showcase the effectiveness of the law for dilute solutions of gases that don't react with the solvent. Some values for
k include:
- O2 : 4.34×104 atoms
- CO2 : 1.64×103 atoms
- H2 : 7.04×104 atoms
when these gases are dissolved in
water at 299
Kelvins