A student investigates the neutralisation of acid in a model wastewater sample. They add 0.15 g portions of solid magnesium hydroxide, Mg(OH)2\text{Mg(OH)}_2Mg(OH)2, to 30 cm3 of dilute sulfuric acid, H2SO4\text{H}_2\text{SO}_4H2SO4, recording the pH after each addition.
Explain why the mixture must be stirred continuously for a short time after adding each portion of magnesium hydroxide before the pH is measured.
Practise Edexcel GCSE Chemistry Acids with exam-style questions for Foundation and Higher tier. 100 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.