Why is the half equation of hydrochloric acid 2 H+ + 2 e- H2  What happened to Cl?

1 Answer | Add Yours

justaguide's profile pic

justaguide | College Teacher | (Level 2) Distinguished Educator

Posted on

A half reaction equation is used to show either the oxidation or the reduction process in the equation.

For the given example, hydrochloric acid dissociates as `HCl -> H^+ + Cl^-` .

The reduction half reaction equation is `2H^+ + 2e^-1-> H_2(g)` .

The `Cl^-` ion combines with the positive ion of the chemical that the acid is reacting with and forms a compound with it. For example, if HCl reacts with sodium metal.

`HCl -> H^+ + Cl^-`

`2H^+ + 2e^-1-> H_2(g)`

and `Na^+ + Cl^(-) -> NaCl`

The Cl in HCl takes part in the other half of the reaction, it is not shown in this half reaction equation as that does not have any relevance here.

We’ve answered 319,644 questions. We can answer yours, too.

Ask a question