Topic 12 - Acid-Base Equilibria

Question 1

What is a Bronsted Lowry acid?

Answer 1

proton donor, release hydrogen ions when they are mixed with water. Combine with H2O to form hydroxonium ions, H3O+

Question 2

What is a Bronsted Lowry base?

Answer 2

proton acceptor, when in solution they grab hydrogen ions from water molecules

Question 3

What happens to strong acids?

Answer 3

Dissociates almost completely in water, Nearly all H+ ions will be released. Equilibrium lies extremely far to the right

Question 4

What happens to strong bases?

Answer 4

Dissociate almost completely in water, equilibrium lies extremely far to the right

Question 5

What happens to weak acids?

Answer 5

dissociates only slightly in water, so only small numbers of H+ are formed. Equilibrium lies to the left

Question 6

What happens to weak bases?

Answer 6

Only slightly protonate in water, equilibrium lies over to the left

Question 7

What are conjugate pairs?

Answer 7

Species that are linked by the transfer of a proton. Always on opposite sides of a reaction

Question 8

What is the standard enthalpy change of neutralisation?

Answer 8

The enthalpy change when solutions of an acid and a base react together, under standard conditions

Question 9

What happens to acids and bases when they react in neutralisation reactions?

Answer 9

• a salt and water is produced
• neutral solution produced when concentration of H+ and OH- are equal - react to form water
• Enthalpy of dissociation varies depending on weak acid or base so standard enthalpy of neutralisation varies
• In strong bases and acid no dissociation occurs, standard enthalpy of neutralisation is very similar for all reaction