S-Cool Revision Summary
The Bronsted-Lowry theory states that an acid is a substance which donates protons, and a base is a substance that accepts protons.
The equilibrium law can be applied to aqueous solutions of acids.
For example, the following equilibrium is established in an aqueous. solution of ethanoic acid:
CH3COOH(aq) + H20(l) CH3COO-(aq) + H30+(aq)
The equilibrium constant is given by:
Ka is the Acid dissociation constant which is a measure of the strength of an acid.
pKa = lgKa - for most acids this gives the range of values between 0-14. Strong acids have low pKa values.
Kw is the ionic product of water, it is based on the equilibrium that occurs due to waters ability to self-ionise.
Kw = [H+][OH-]
At 25°C it has a value of 1.0 x 10-14
pKw = 14.
To calculate pH:
pH = -lg [H+]
A buffer is a solution in which the pH of which does not change significantly when small amounts of acid or base is added to it.
Solubility product is a measure of a compounds solubility: Ksp.