Question

Is this half-reaction H2(g) + 2 OH-(aq) ===> 2 H2O(l) = 2 e

reduction or oxidation?

Answer 1

H2 goes from zero on the left [H2[(g) to +1 on the right (in H2O). The O is -2 on the left and -2 on the right. The H (in OH^-) is +1 on the left and +1 on the right (in H2O). So the change is from H2(g) on the left at zero to +1 on the right in H2O. To go from zero to +1 H had to (lose,gain) electrons.

Answer 2

This is an oxidation reaction then, right?