Physics question?

Question

The question is:
If you separated the elements of the product of this reaction, which type of reaction would this be?

The equation is this:
2H2 + O2 = 2 H2O

Answer 1

I think you're referring to hydrolysis

Answer 2

Water can be separated back into hydrogen and oxygen via electrolysis:

2H2O(l) + 2e− --->H2(g) + 2OH−(aq)
O2(g) + 4H+(aq) + 4e−---> 2H2O(l)

Hence overall 2H2O(l) ---> 2H2(g) + O2(g)

Platinum electrodes are used.