Question

2H2O(I) + energy --> 2H2(g) + O2(g)

a. Write the balanced half reaction taking place at the positive electrode. What is the gas being produced here?

b. Write the balanced half reaction taking place at the negative electrode. What is the gas being produced here?

Answer 1

a. Positive electrode (anode) half-reaction:

2H2O(l) → O2(g) + 4H^+(aq) + 4e^-

The gas being produced at the positive electrode is oxygen (O2(g)).

b. Negative electrode (cathode) half-reaction:

2H^+(aq) + 2e^- → H2(g)

The gas being produced at the negative electrode is hydrogen (H2(g)).

Overall reaction:

2H2O(l) → 2H2(g) + O2(g)