Explain5 marksChallenge
The boiling points of the halogens increase down Group 17: chlorine boils at −34 °C, bromine at 59 °C and iodine at 184 °C. Explain this trend, referring to the intermolecular forces involved.
CAIE A Level Chemistry 9701 · Group 17
Group 17: explain question
How this question is marked
5 marks, so the mark scheme is looking for about 5 separate creditworthy points. Making the same point twice in different words earns it once.
Explain means: Give the reasons or the mechanism: why or how something happens. Link each point to the next with because, so or which means. A list of facts with no links usually loses the reasoning marks.
More Group 17 questions
- 7 marks · The hydrogen halides HF, HCl, HBr and HI can be formed by direct combination of the elements. Samples of each hydrogen halide are heated…
- 5 marks · The elements of Group 17 react with hydrogen to form hydrogen halides, and the hydrogen halides decompose on heating. (a) State and…
- 7 marks · Fluorine reacts with hydrogen even in the dark at room temperature, whereas chlorine requires light or a flame, and iodine only reacts…
- 7 marks · Chlorine, bromine and iodine are molecular elements. In terms of their electron arrangements and the forces between their molecules…
- 7 marks · Chlorine undergoes different reactions with cold and hot aqueous sodium hydroxide and is also used in water purification. (a) Describe…
- 6 marks · Bromine is a liquid at room temperature and pressure, whereas chlorine is a gas. Suggest why bromine has a higher boiling point than…
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.