CAIE A Level Chemistry 9701 · Group 17
A student has an aqueous solution of a sodium halide, NaX, where X is a halogen. In one test, acidified aqueous silver nitrate is added, producing a cream precipitate that dissolves when dilute aqueous ammonia is added. In a second test, concentrated sulfuric acid is added to the solid sodium halide, producing a mixture of gases including a pungent gas that turns acidified aqueous potassium dichromate green, and a yellow solid.
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.
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.