# If acid releases proton then how can a proton react with another proton to form hydrogen gas? [duplicate]

As we know that acid releases proton (H+ ion) when dipped in water hydrogen has a proton and electron only . To form H+ hydrogen releases 1 electron and it becomes proton. But when Acid reacts with metals hydrogen ion reacts with another hydrogen ion ( which is nothing but proton ) to form hydrogen gas then how can it be possible that one proton reacts with another proton to form hydrogen gas?

• They can't, of course. One proton is positively charged, and so is another. There must be something else to it. – Ivan Neretin Jun 16 '20 at 18:09

## 2 Answers

A proton does not react with another proton, as you state. It reacts with a metal. And this metal gives one electron to one proton. This makes a Hydrogen atom, then a Hydrogen molecule. Finally the metal becomes a positively charged cation, which passes into solution

Usually there is some form of a redox reaction happening there, for example like $$\ce{M(s) + 2H+(aq) \to M^{2+} (aq) + H2(g)}$$ where $$M$$ is just some metal (like copper, iron, etc...) reducing hydrogen to its elemental/gaseous form.