Topic 12 - Acid-Base Equilibria
Acids and Bases
What is the difference between an acid and a base in terms of protons?
an acid releases protons e.g. NH4+
a base accepts protons e.g. OH-
Describe the difference between a strong and weak acid
strong acids dissociate almost completely in water - nearly all H+ ions will be
released
weak acids dissociate only slightly in water
same with bases
Acid + base → ?
acid + base → salt + water
Define the enthalpy change of neutralisation
the enthalpy change of neutralisation is the enthalpy change when solutions of
an acid and a base react together under standard conditions to produce 1 mole
of water
Describe the difference between the neutralisation of strong compared to
weak acids and bases
strong acids and bases
produce very similar enthalpies of neutralisation becuase solutions completely
dissociate
weak acids and bases
ions only slightly dissociate so other enthalpies occur
so enthalpies of neutralisation can vary a lot
pH
Topic 12 - Acid-Base Equilibria 1
, State the equation to calculate pH
What is the difference between monoprotic and polyprotic acids?
monoprotic acids can release only one proton into solution
polyprotic acids can release more than one into solution
What is the equilibrium constant Ka used for?
weak acids and bases becuase they only slightly dissociate in solution to form
an equillibrium mixture
Describe whether or not the pH of pure water is always 7
no, as temp increases equ moves to the RHS / Kw increases
so [H+] ions increases
hence pH descreases / pH < 7
Ionic product of water
Describe how and what ions water contains with equation
water can act as an acid by donating a proton and as a base by accepting a
proton
Topic 12 - Acid-Base Equilibria 2
Acids and Bases
What is the difference between an acid and a base in terms of protons?
an acid releases protons e.g. NH4+
a base accepts protons e.g. OH-
Describe the difference between a strong and weak acid
strong acids dissociate almost completely in water - nearly all H+ ions will be
released
weak acids dissociate only slightly in water
same with bases
Acid + base → ?
acid + base → salt + water
Define the enthalpy change of neutralisation
the enthalpy change of neutralisation is the enthalpy change when solutions of
an acid and a base react together under standard conditions to produce 1 mole
of water
Describe the difference between the neutralisation of strong compared to
weak acids and bases
strong acids and bases
produce very similar enthalpies of neutralisation becuase solutions completely
dissociate
weak acids and bases
ions only slightly dissociate so other enthalpies occur
so enthalpies of neutralisation can vary a lot
pH
Topic 12 - Acid-Base Equilibria 1
, State the equation to calculate pH
What is the difference between monoprotic and polyprotic acids?
monoprotic acids can release only one proton into solution
polyprotic acids can release more than one into solution
What is the equilibrium constant Ka used for?
weak acids and bases becuase they only slightly dissociate in solution to form
an equillibrium mixture
Describe whether or not the pH of pure water is always 7
no, as temp increases equ moves to the RHS / Kw increases
so [H+] ions increases
hence pH descreases / pH < 7
Ionic product of water
Describe how and what ions water contains with equation
water can act as an acid by donating a proton and as a base by accepting a
proton
Topic 12 - Acid-Base Equilibria 2
