A student tests a solution of a sodium salt to see if it contains sulfate ions. They start with 15.0 g of the sodium salt solution in a test tube. First, they add 2.5 g of dilute hydrochloric acid. Next, they add 6 drops of barium chloride solution. Each drop has a mass of 0.15 g. Calculate the total mass of the mixture at the end of this chemical test.
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.