What is a neutralisation reaction ?
When acids and bases react with each other, forming a salt and water.
What is a Bronsted base ?
The salt of a weak acid
What is Kh of a salt ?
The hydrolysis constant of the salt.
What is the equation for a strong acid + a strong base ?
E.g. HCl + NaOH
HCl + NaOH ⇔ NaCl + H2O
N.B. Salts in which the cation and anion are both conjugates of a strong base and a strong acid form neutral solutions.
What is the equation for strong acid and a weak base ?
E.g. HCl + NH3
HCl + NH3 ⇔ NH4Cl
N.B. Salts that are formed based on a strong acid and a weak base for acidic solutions.
What is the equation for a weak acid and a strong base ?
E.g. HOAc + NaOH
HOAc + NaOH ⇔ NaOAc + H2O
What is the equation for a weak acid and a weak base ?
E.g. HOAc + NH3
HOAc + NH3 ⇔ NH4OAc
The pH is dependent on the relative strengths of the acid and the base
What is a buffer ?
A solution that resists change in pH when a solution is diluted , or a small amount of acid or base is added.
What does a buffer solution consist of ?
A mixture of a weak acid and its salt, or a weak base and its salt.
Why are buffers made up of weak acids/bases, and not strong ?
Strong acids/bases do not have any buffering capacity as the dissociation would be irreversible.
When is the buffering capacity of a solution at its maximum ?
When pH = pKa
What is an amphoteric species ?
A substance, e.g. water, that can act as either an acid or a base. Many metal oxides and hydroxides also act amphoterically.
What is the general purpose of a titration reaction ?
To determine the concentration of a given sample of acid or base (analyte).
What is the end/equivalent point of a titration ?
They are not always the same thing.
The end point is where a physical change in solution (e.g. colour) occurs.
The equivalence point is where a reaction is theoretically complete.
In practice, this difference can usually be seen as negligable.