Question

Which are not oxidative reaction?
(look at the image)​

Answer 1

Cu²+ e ----> Cu+

This is not oxidation as it gain electron .

Oxidation reaction means addition of oxygen or removal of hydrogen

or in other words loss of electrons

Mg ----> Mg²+ + 2e

this is oxidation reaction as Mg loss 2e to become +2

Sn³+ -----> Sn4+ + 2e

this is oxidation reaction as it losses electrons

similarly other are also oxidation.