Six-mark questions
Six-mark questions are extended open response questions. These require longer answers than the structured questions that have fewer marks. It is wise to plan your answer first by making some notes. This will help you to include all the key points.
To gain full marks, you need to:
- support explanations using scientific knowledge and understanding
- use appropriate scientific words
- write clearly and link ideas in a logical way
- maintain a sustained line of reasoning
Writing six-mark answers with Dr Alex Lathbridge
Listen to the full series on BBC Sounds.
How to write six-mark answers in your science GCSE exams.
Six-mark questions often use these command words:
- Describe means you should recall facts, events or processes accurately. You might need to give an account of what something looked like, or what happened.
- Explain means you need to make something clear, or state the reasons for something happening.
- Compare means you need to describe similarities and differences between things. If you are asked to compare X and Y, write down something about X and something about Y, and give a comparison. Do not just write about X only or Y only.
- Evaluate means you must use information supplied, or your own knowledge, to consider the evidence for and against or to identify strengths and weaknesses. You must then complete your answer with a conclusion, stating which is better and why, for example.
Six-mark questions may be synoptic questions, which bring together ideas from two or more topics. For example, a question about fertilisers could include ideas about covalent substances, acids and alkalis, chemical calculations, and effects on the environment.
The answers shown here give marking points as bullet points. You do not usually need to include all of them to gain six marks, but you do need to write in sentences, linking them logically and clearly.
Sample question 1 - Foundation
Question
Describe how to do a titration to find the exact volume of sulfuric acid needed to neutralise 25.0 cm3 of sodium hydroxide solution and then how to obtain pure, dry crystals of sodium sulfate.
[6 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
Your answer can include any of the following:
- rinse the pipette with alkali and the burette with acid
- measure alkali using a pipette into a conical flask and place flask on a white tile
- add a few drops of indicator/suitable named indicator, eg methyl orange/phenolphthalein
- fill the burette with acid and read volume of acid in the burette
- add acid from the burette to the flask slowly, swirling the flask until indicator just changes colour
- read the volume of acid in the burette at the end of titration
- repeat until concordant results are obtained
- mix the same volume of alkali with the volume of acid determined from the titration but do not add indicator
- pour solution into an evaporating basin and heat over a water bath
- stop heating when crystals start to form
- allow water to evaporate until pure crystals remain
- dry crystals using absorbent paper/warm oven
Sample question 2 - Foundation
Question
Describe a safe method for making pure crystals of copper sulfate from copper carbonate and dilute sulfuric acid.
In your method you should name all the apparatus you will use.
[6 marks]
This question is AQA material which is reproduced by permission of AQA.
Your answer can include any of the following:
- place sulfuric acid in a beaker
- add copper carbonate one spatula at a time
- until copper carbonate is in excess or until no more effervescence occurs
- filter with filter paper and funnel
- filter excess copper carbonate
- pour solution into evaporating dish/basin
- heat using Bunsen burner
- pour solution into an evaporating basin and heat over a water bath
- stop heating when crystals start to form
- allow water to evaporate until pure crystals remain
- dry crystals using absorbent paper/warm oven
- wear eye protection
Sample question 3 - Higher
Question
Part of the reactivity series is shown below.
- Calcium
- Magnesium
- Zinc
- Iron
- Copper
Compare how the different metals displayed here react with dilute hydrochloric acid.
[6 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
Your answer can include any of the following:
- calcium, magnesium, zinc and iron react with dilute hydrochloric acid
- the products are hydrogen gas...
- ...and a chloride salt
- the reactions get less vigorous from top to bottom of the reactivity series
- calcium reacts very vigorously...
- ...and copper does not react at all
- the greater the reactivity of the metal, the greater its tendency to form positive ions
- calcium has a high tendency to lose electrons/form positive ions
- copper has a low tendency to lose electrons/form positive ions
Sample question 4 - Higher
Question
Electrolysis of acidified water can produce hydrogen and oxygen.
The apparatus for the electrolysis is:
- water containing some dilute sulfuric acid
- two graphite rods
- a suitable container for the electrolysis reaction
- a suitable source of electricity
- test tubes
Describe how to use the apparatus to electrolyse acidified water, and how to test the gases to show that they are hydrogen and oxygen.
Include a diagram in your answer.
[6 marks]
This question has been written by a Bitesize consultant as a suggestion to the type of question that may appear in an exam paper.
Your answer can include any of the following:
Experiment set up:
- acidified water in container (eg beaker)
- graphite rods in acid
- attach rods to electrical supply
- DC supply
- test tubes to collect gases
Test for hydrogen:
- lighted splint
- squeaky pop
Test for oxygen:
- glowing splint
- relights
Note: No diagram shown in this sample answer, however, if instructed one should be given in exam conditions.
