The acid used in a standard hydrogen electrode to provide a 1 mol dm–3 solution of
hydrogen ions is
A ethanoic acid.
B phosphoric(V) acid.
C sulfuric acid.
D hydrochloric acid.
It's either C or D but I don't exactly know which one.
Which is the correct answer and WHY?
If we are talking about 1 M H+ solution, the C and the D both are correct. If we are talking about 1 M acid solution, only HCl is applicable(D), because it is right only for 0.5 M solution of H2SO4.