Question

Redox refers to a substance gaining an electron and releasing what?

Answer 1

Redox chemistry relates to electron transfer: the formal loss or gain of electrons.

Explanation:

A substance that accepts electrons is an oxidant, an oxidizing agent:

`1/2O_2 + 2e^(-) rarr O^(2-)` `i.`

In accepting the electrons it has in fact been reduced.

A substance that donates electrons is an reductant, a reducing agent, and in losing those electrons it is itself manifestly oxidized:

`Na rarr Na^(+) + e^(-)` `ii`

We include electrons in these half equations, as a means to help balance with respect to charge. We add the half equation together to remove the electrons from the final redox equation:

`(i)+2xx(ii)`

`2Na + O_2 rarr Na_2O`

In all instances, charge must be balanced as well as mass.