An aqueous solution of sodium sulfate, Na2SO4(aq)\text{Na}_2\text{SO}_4(\text{aq})Na2SO4(aq), is electrolysed using inert platinum electrodes in the presence of a universal indicator. Initially, the solution is neutral (pH 7\text{pH } 7pH 7) and green.
Which of the following correctly describes the local colour changes of the universal indicator and the ratio of the volume of gas collected at the cathode to that at the anode?
Anode region: Red; Cathode region: Blue-violet; Volume ratio (Cathode : Anode) = 2:12 : 12:1
Anode region: Red; Cathode region: Blue-violet; Volume ratio (Cathode : Anode) = 1:21 : 21:2
Anode region: Blue-violet; Cathode region: Red; Volume ratio (Cathode : Anode) = 2:12 : 12:1
Anode region: Red; Cathode region: Blue-violet; Volume ratio (Cathode : Anode) = 1:11 : 11:1
Electrolytic processes Questions
Practise Edexcel GCSE Chemistry Electrolytic processes 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.