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:
Six-mark questions often use these command words:
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:
Questions courtesy of Eduqas.
Figure 1 shows the reaction profile for a chemical reaction.
Explain in detail what the diagram shows.
In your answer, state what each arrow represents, and refer to the bond energies of the reactants and products. [6 marks]
The relative energy of the products is greater than the relative energy of the reactants. 
The reaction is endothermic. 
The arrow on the right represents the overall energy change of the reaction. 
The arrow on the left shows the activation energy. 
The energy needed to break existing bonds in the reactants... 
...is greater than the energy released from forming new bonds.