Why can’t you just put put hydrogen and oxygen in a tank (with a 2:1 ratio) and make water? What would water be without both?

Question

Why can’t you just put put hydrogen and oxygen in a tank (with a 2:1 ratio) and make water? What would water be without both?

In: 2

Answer 1

You pretty much can do that. The reaction is exergonic, which means it releases energy, so it could be used to power cars or whatever and the only waste is water. The problem is that getting raw oxygen and hydrogen is expensive and energy intensive so it is cost prohibitive.