Paper 2 Corrections

Question 1

Why are + ions more reactive down the group?

Answer 1

Atoms become larger/outer electron
becomes further from the nucleus

Outer electron more easily lost / less
energy needed to lose outer electron

Question 2

Give reasons why are ethanol, propanol and butanol are members of the same homologous series

Answer 2

all have –OH group/ hydroxyl group / same
functional group (1)
* same general formula/ CnH2n+1OH (1)
* formulae differ by CH2 units (1)
* react similarly with oxygen/all burn to form
carbon dioxide and water (1)
* trend in physical properties

Question 3

What is the equation for the oxidation of propanol

Answer 3

propanol + oxygen → propanoic acid + water
Alcohol + H20 -> carboxylic acid + water

Question 4

Why do longer hydrocarbons have higher melting points?

Answer 4

boiling points increase as the number of
carbon atoms increases
because {stronger forces between molecules /
(increased / more) intermolecular forces

Question 5

If in electrolysis, how do you prove a substance is ionic?

Answer 5

ammeter shows current

Question 6

The green iron(II) hydroxide precipitate gradually turns brown when exposed to air.
Explain this observation

Answer 6

Iron(II) ions (/hyrdroxide) oxidised (by air) (1)
It goes brown due to formation of iron(III) hydroxide