A student is given an aqueous solution of an unknown inorganic salt. They perform two chemical tests to identify the ions:
To the first sample, they add dilute hydrochloric acid followed by barium chloride solution. A white precipitate forms that does NOT dissolve in the acid. Identify the chemical formula of the anion.
To the second sample, they add sodium hydroxide solution. A brown precipitate forms. Identify the chemical formula of the cation.
35 exam-style questions on Edexcel IGCSE Chemistry Chemical tests. Each one has a worked solution and a mark scheme showing where the marks go.