In an environmental monitoring investigation, a technician tests a soil runoff sample for the presence of sulfate ions. Upon adding an aqueous solution of barium chloride, a dense white precipitate of barium sulfate, BaSO4\text{BaSO}_4BaSO4, is observed.
Write the ionic equation, including state symbols, for this precipitation reaction.
230 exam-style questions on Edexcel GCSE Chemistry 1.1 Formulae, equations and hazards, covering 1.1.1 Formulae, word and balanced equations, 1.1.2 Balanced ionic equations, and 1.1.3 Hazard symbols and risk in practical work. Each one has a worked solution and a mark scheme showing where the marks go.