Acids and bases 1

Question 1

What are electrolytes (3)

Answer 1

1. Electrolytes are solutes that give cations (+) &anions (-) when in solution.
2. Strong electrolytes fully ionise (dissociate) in an irreversible reaction
3. Weak electrolytes partially ionise in an equilibrium reaction

Question 2

What are conjugate pairs (6)

Answer 2

1. conjugate = right-hand side
2. Base or acid = accepts/donates protons
3. Weak acids have strong conjugate bases.
4. Strong bases have weak conjugate acids.
5. ⇌
6. For acids and bases, adding more water will shift equilibria to the right due to Le Chatelier’s principle

Question 3

What are amphoteric substances (3)

Answer 3

1. React with both acids and bases
2. All amphiprotic species are amphoteric, but not all amphoteric substances are amphiprotic, e.g. VO2
3. VO2 acts here as (i) a Lewis base and (ii) a Lewis acid. (accepts/donates lone pairs, not protons)

Question 4

What are Lewis acids and bases, and Brönsted-Lowry acids and bases (2)

Answer 4

Lewis = electron pair acceptor/donor.

Brönsted-Lowry = proton acceptor/donor

Question 5

What are the types of solvents (4)

Answer 5

1. Amphiprotic: Donates/accepts protons, e.g. H2O
2. Protogenic: Donates protons, e.g. H2SO4
3. Protophillic: Accepts protons e.g. NH3
4. Aprotic: Neither accepts nor donates protons

Question 6

What happens with KW and temperature

Answer 6

KW increases with temperature

Question 7

What does amphiprotic mean

Answer 7

both accept or donate protons