An environmental chemist is investigating how temperature affects the rate of precipitation of calcium sulfate when sulfuric acid is mixed with wastewater containing calcium ions.
The reaction forms a fine, white precipitate of calcium sulfate, which gradually makes the mixture turbid (cloudy) and reduces light transmission.
To obtain more precise measurements than the traditional 'disappearing cross' method, the chemist decides to use a continuous monitoring system with a light sensor and a data logger, as shown in the diagram below.
Describe a method the chemist could use to measure the time taken for the mixture to reach a specific level of turbidity.
Practise Edexcel GCSE Chemistry Rates of reaction with exam-style questions for Foundation and Higher tier. 166 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
