CAIE A Level Chemistry 9701 · Chemical bonding
Water, , boils at 373 K. Hydrogen sulfide, , the analogous compound of sulfur, boils at 213 K.
Compare the types of intermolecular force present in water with those present in hydrogen sulfide. Use your comparison to explain why water has the higher boiling point and why water shows a relatively high surface tension. Explain why ice is less dense than liquid water at 0 °C.
7 marks, so the mark scheme is looking for about 7 separate creditworthy points. Making the same point twice in different words earns it once.
Compare means: Give similarities or differences between two things, and say which side each point belongs to. Write each point as a pair, for example: A is X, whereas B is Y. Two separate descriptions rarely earn the marks.
Written by Markquill to follow the Cambridge International syllabus. Markquill is independent and is not affiliated with or endorsed by Cambridge International.