When dilute hydrochloric acid reacts with sodium thiosulfate solution, a precipitate of sulfur is formed, which makes the mixture go cloudy. Toxic sulfur dioxide gas (SO2SO_2SO2) is also produced as a byproduct.
Give one safety precaution that the student should take when carrying out this experiment, other than wearing safety goggles.
127 exam-style questions on Edexcel GCSE Chemistry 8.1 Rates of reaction, covering 8.1.1 Measuring and interpreting rates of reaction, 8.1.2 Collision theory and the factors affecting rate, and 8.1.3 Catalysts and enzymes. Each one has a worked solution and a mark scheme showing where the marks go.