Electrolytic cells help

[Brittanyany17]

Hey guys
Our chem class had a sac today and  I was wondering about this question, it was something like this:
When would a universal indicator not be useful for identifying the presence of H+ and OH- in a electrolytic cell?
We used sodium sulfate, sulfuric acid, zinc chloride, potassium iodide and copper nitrate

[BakedDwarf]

Hey guys
Our chem class had a sac today and  I was wondering about this question, it was something like this:
When would a universal indicator not be useful for identifying the presence of H+ and OH- in a electrolytic cell?
We used sodium sulfate, sulfuric acid, zinc chloride, potassium iodide and copper nitrate

Haha i think we did the same SAC in a different school and i too was stuck on that question.

I guessed that using universal indicator for coloured solutions such as copper nitrate would not be useful in determining H+/OH- ions  because the colour change cannot be accurately determined.

[Brittanyany17]

Ahh damn that sounds about right thanks - would sulfuric acid matter? because its acidic to begin with?

[Bruzzix]

I had this question on my SAC too. My answer was that it would not be useful when chlorine gas is produced as this decolourises the universal indicator. Now that I think about it, BakedDwarf's answer is probably better though