This question is about analytical techniques used to identify cations and anions in aqueous mixtures.
State the characteristic flame colour produced by lithium ions (Li+\text{Li}^+Li+) during a flame test.
Identify a metal ion that produces a distinct pale green flame.
Explain why flame tests are generally unreliable for identifying individual metal cations when they are present in a mixed sample.
An analyst acidifies an unknown sample containing a halide ion with dilute nitric acid and then adds aqueous silver nitrate. A cream precipitate is observed. Name the halide ion present.
Describe a chemical test, including reagents and observations, to confirm the presence of sulfate ions (SO42−\text{SO}_4^{2-}SO42−) in an aqueous solution.