A student added solid magnesium oxide to 50 cm³ of dilute hydrochloric acid and monitored the change in pH. The results are shown in Figure 1.

Using Figure 1, give the mass of magnesium oxide required to make a neutral mixture.
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.