A student investigates the neutralisation of an acid by adding solid calcium hydroxide, Ca(OH)2\text{Ca(OH)}_2Ca(OH)2, to dilute nitric acid, HNO3\text{HNO}_3HNO3.
The student's method is as follows:
Step 1: Measure 120 cm3 of dilute nitric acid into a clean beaker.
Step 2: Add a 0.3 g portion of calcium hydroxide powder to the beaker.
Step 3: Measure and record the pH of the mixture.
Step 4: Repeat Steps 2 and 3 until the pH remains constant.
State one action that the student should take immediately after Step 2 to ensure that the calcium hydroxide reacts as fully as possible with the acid before the pH is measured.
Practise Edexcel GCSE Chemistry Acids with exam-style questions for Foundation and Higher tier. 276 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.
