12.1 THEORIES TO EXPLAIN REACTIONS OF
ACIDS & BASES
04 December 2021
17:35
Acids dissociate when dissolved in water, forming ions.
The stronger the acid, the more dissociation.
Strong acids fully ionise and dissociate in water.
Weak acids partially ionise and dissociate in water.
12.2 ACIDS, BASES & PROTON TRANSFER
04 December 2021
19:09
The Bronsted-Lowry theory states that acids donate protons to water molecules
which accept the protons, acting as the base.
Forms hydrated H+ ions, hydroxonium ions, H3O+.
A base is a molecule or ion which can accept protons from an acid.
Has lone pair of electrons to form a dative covalent bond with a proton.
An acid turns into its conjugate base when it loses a proton.
A base turns into its conjugate acid when it gains a proton.
A conjugate acid-base pair is an acid and base which can be converted from one
another by proton transfer.
, 12.3 THE pH SCALE
05 December 2021
11:39
The pH scale is a measure of H+ ion concentration.
pH = -log[H+(aq)]
The higher the H+ concentration, the lower the pH.
A strong monoprotic acid will fully dissociate.
[H+] = concentration of acid.
One mole of acid forms one mole of H+.
Strong polyprotic acids can lose more than one proton when they dissociate.
Second ionisation suppressed by the first ionisation, and so [H⁺] doesn’t equal
2x acid concentration.
Kw, the ionic product of water, depends on [OH-] and [H+].
Water can act as both an acid by donating, or a base by accepting protons.
Or more simply as:
As water only dissociates a minimal amount, equilibrium lies to the left.
Much more water compared to H+ and OH-, so the concentration of water is
considered constant.
Multiplying Kc by [H2O] gives the ionic product of water, Kw.
Equilibrium constant for the ionisation of water.
ACIDS & BASES
04 December 2021
17:35
Acids dissociate when dissolved in water, forming ions.
The stronger the acid, the more dissociation.
Strong acids fully ionise and dissociate in water.
Weak acids partially ionise and dissociate in water.
12.2 ACIDS, BASES & PROTON TRANSFER
04 December 2021
19:09
The Bronsted-Lowry theory states that acids donate protons to water molecules
which accept the protons, acting as the base.
Forms hydrated H+ ions, hydroxonium ions, H3O+.
A base is a molecule or ion which can accept protons from an acid.
Has lone pair of electrons to form a dative covalent bond with a proton.
An acid turns into its conjugate base when it loses a proton.
A base turns into its conjugate acid when it gains a proton.
A conjugate acid-base pair is an acid and base which can be converted from one
another by proton transfer.
, 12.3 THE pH SCALE
05 December 2021
11:39
The pH scale is a measure of H+ ion concentration.
pH = -log[H+(aq)]
The higher the H+ concentration, the lower the pH.
A strong monoprotic acid will fully dissociate.
[H+] = concentration of acid.
One mole of acid forms one mole of H+.
Strong polyprotic acids can lose more than one proton when they dissociate.
Second ionisation suppressed by the first ionisation, and so [H⁺] doesn’t equal
2x acid concentration.
Kw, the ionic product of water, depends on [OH-] and [H+].
Water can act as both an acid by donating, or a base by accepting protons.
Or more simply as:
As water only dissociates a minimal amount, equilibrium lies to the left.
Much more water compared to H+ and OH-, so the concentration of water is
considered constant.
Multiplying Kc by [H2O] gives the ionic product of water, Kw.
Equilibrium constant for the ionisation of water.
