The qualitative-analysis question in 9701 Paper 3 rewards precise observations and conclusions that follow from them. Test an unknown salt in virtual test tubes, including magnesium, manganese(II) and barium, halides with aqueous ammonia, and sulfate against sulfite. A new unknown every time.
This trainer needs JavaScript.
Colour, precipitate, and its behaviour in excess and on standing: for example “off-white precipitate, insoluble in excess, turning brown on standing” for manganese(II).
The colour of the silver halide and its solubility in aqueous ammonia: chloride soluble, bromide partially soluble, iodide insoluble.
Both give a white precipitate with barium ions; only barium sulfite dissolves in excess dilute strong acid.
Ions identified from the evidence, using the notes printed in the paper.
The marking follows the conventions in published Cambridge mark schemes. The experiments, readings and wording on this page are our own.