Structured questions
Simple recall questions are usually worth one mark. They often have command words like 'give...', 'state...', 'name..' or 'identify...'. Some questions may ask you to state two things, rather than just one, and will be worth two marks.
Structured questions, with command words such as 'Describe...' or 'Explain...', will be worth two or more marks:
- if you are asked to describe something, you need to give an account but no reason
- if you are asked to explain something, you must give reasons or explanations
More complex structured questions will be worth three or four marks. They include questions with complex descriptions and explanations, questions in which you need to compare and contrast two different things, or calculations with several stages.
The mark schemes given here may show answers as bullet points. This is to show clearly how a mark can be obtained. However, it is important that your answer is written in a logical manner, the points are linked to each other, and are relevant to the question.
Edexcel questions courtesy of Pearson Education Ltd.
Learn about command words with Dr Alex Lathbridge
Listen to the full series on BBC Sounds.
Understanding the different command words in your science GCSE exams.
Sample question 1 - Foundation
Question
A sample of each of three hydrocarbons, X, Y and Z, was shaken with bromine water. Bromine water is orange coloured. The results are:
X orange mixture becomes colourless
Y orange mixture becomes colourless
Z mixture remains orange
Using the results, comment on the structures of the hydrocarbons X, Y and Z.
[2 marks]
- X and Y are both unsaturated/contain double bonds/they are alkenes [1]
- Z is saturated/contains no double bonds/it is an alkane [1]
Sample question 2 - Foundation
Question
Ethanol, C2H5OH, can be oxidised to form ethanoic acid.
Draw the structure of a molecule of ethanoic acid, showing all the covalent bonds.
[2 marks]
Structure:
- structure with two carbon atoms with three hydrogen atoms joined to one of them [1]
- rest of structure correct [1]
Sample question 3 - Higher
Question
The table shows some properties of steel and a polyester fibre material.
| Property | Steel | Polyester |
| Density | 7.85 g/cm3 | 1.44 g/cm3 |
| Relative strength | 1 | 5 |
| Flexibility | Low | High |
| Resistance to corrosion | Low | High |
| Property | Density |
|---|---|
| Steel | 7.85 g/cm3 |
| Polyester | 1.44 g/cm3 |
| Property | Relative strength |
|---|---|
| Steel | 1 |
| Polyester | 5 |
| Property | Flexibility |
|---|---|
| Steel | Low |
| Polyester | High |
| Property | Resistance to corrosion |
|---|---|
| Steel | Low |
| Polyester | High |
Body armour, such as a bullet-proof vest, could be manufactured using either of these materials.
Explain two reasons why the polyester is preferred to steel as the material for body armour.
[4 marks]
Two from the following:
- it is lighter/has a lower density/than steel [1] so it is easier/more comfortable to wear [1]
- it is stronger [1] so it is less likely to be penetrated [1]
- it is more flexible [1] so it is easier/more comfortable to wear [1]
- does not corrode/rust [1] so it will last longer [1]
Sample question 4 - Higher
Question
An alcohol A, with molecular formula C2H5OH is oxidised to a compound B with molecular formula C2H4O2.
Compound B is not an alcohol and is a member of another homologous series.
(a) State the name of this homologous series.
[1 mark]
(b) Draw the structure of a molecule of compound A and a molecule of compound B, showing all covalent bonds.
[2 marks]
- (a) Carboxylic acids [1]
- (b) Structure of A:
- Structure of B:
