Six-mark questions

Six-mark questions are extended open response questions. These require longer answers than the structured questions. It is wise to plan your answer rather than rushing straight into it, otherwise you may stray away from the key points.

Most questions on exam papers have mark schemes that give key points that are given marks. The six-mark questions are marked differently: they use a levels-based mark scheme. This type of mark scheme is used because these questions are more open-ended. To gain full marks, you need to:

  • support explanations using scientific knowledge and understanding
  • use appropriate scientific words and terms
  • write clearly and link ideas in a logical way
  • maintain a sustained line of reasoning, rather than getting lost or bogged down

Six-mark questions often use these command words:

  • Describe - you need to give an account but no reason
  • Explain - you must give reasons or explanations
  • Devise - you must plan or invent a procedure using your scientific knowledge and understanding
  • Evaluate - you must review information, including identifying strengths and weaknesses, and make a supported conclusion

Six-mark questions may be synoptic questions. These questions 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 full sentences, linking them logically and clearly.

Answers are placed in three marking bands:

  • 1 to 2 marks for answers showing limited content and reasoning and with significant omissions.
  • 3 to 4 marks for answers that give some relevant points, with linking and reasoning and with fewer omissions.
  • 5 to 6 marks for answers that link most of the relevant points, with good links and reasoning. They will have few, if any, omissions.

Questions courtesy of Eduqas.

Sample question 1 - Foundation

Question

In industry, crude oil is separated into useful fractions - petroleum gases, petrol, naphtha, paraffin, diesel oil, lubricating oil and bitumen.

Write an account of this industrial process.

Include in your answer:

  • the name of the separation method
  • what crude oil is
  • a description of how crude oil is separated

[6 marks]

Your answer should include the following:

  • this method of separation is called fractional distillation
  • crude oil is a mixture of hydrocarbons
  • the crude oil is heated and vaporised before entering the column
  • smaller/lower boiling hydrocarbons will rise in the column and condense higher up the column
  • hydrocarbons with similar boiling points condense at the same level in the column
  • boiling point depends on the size of the molecule - larger molecules have higher boiling points

[6]

Sample question 2 - Higher

Question

Crude oil is a finite resource.

Explain why the fact that crude oil is a finite resource is a problem, and describe how cracking maximises the amounts of useful substances obtained from crude oil. [6 marks]

  • humans rely on substances obtained from crude oil for many purposes...
  • ...including as a fuel for heating and vehicles...
  • ...and to make other products/as a feedstock for the chemical industry
  • cracking breaks bigger molecules to smaller ones…
  • ...by heating them to a high temperature...
  • ...in the presence of a catalyst
  • the smaller molecules produced by cracking are required for vehicle fuels...
  • ...and to make polymers/other useful substances/materials

[6]