From the Standard Potential Table in your general chemistry textbook: Which reaction has been chosen as the 'standard' against which every other reaction is measured?

Question

A. 2H+ + 2e– ==> H2
B. O2 + 4H+ + 4e– ==> 2H2O
C. F2 + 2e– ==> 2F–
D. Li+ + e– ==> Li
E. H2 + 2e– ==> 2H–

Answer 1

Read about the standard hydrogen electrode.