Consider an electrolyte adsorbing at water air interface. It can be represented as chemical equation as
where represents . Using Gibbs equation we can write
Assuming surface is neutral i.e. equal number of anion and cation at the surface so
is mean ionic activity which is practically more easy to measure then and .
where is the concentration(amount) of salt put in. Reduction in surface tension depends on how much molecules are adsorbed on the surface.
adsorbing at water air interface. It can be represented as chemical equation as
where 
represents 
. Using Gibbs equation we can write
is mean ionic activity which is practically more easy to measure then 
and 
.
is the concentration(amount) of salt put in. Reduction in surface tension depends on how much molecules are adsorbed on the surface.
