Definition+2

 Definition 2 defines Oxidation as a loss of hydrogen atoms . It is not so often used in actual application as there are not many reactions which involve hydrogen. Nevertheless, let's illustrate this definition using two examples below.

__Example 1__ H 2 S(g) + Cl 2 (g) → 2HCl(g) + S(s) H 2 S loses hydrogen to form S. Thus, H 2 S has been oxidised. Cl 2  is the oxidising agent.

__Example 2__ 2NH 3  + 3CuO → N 2  + 3Cu + 3H <span style="color: #800080; font-family: 'Trebuchet MS',Helvetica,sans-serif; vertical-align: sub;">2 <span style="color: #800080; font-family: 'Trebuchet MS',Helvetica,sans-serif;">O NH <span style="color: #800080; font-family: 'Trebuchet MS',Helvetica,sans-serif; vertical-align: sub;">3 <span style="color: #800080; font-family: 'Trebuchet MS',Helvetica,sans-serif;"> loses hydrogen to form N <span style="color: #800080; font-family: 'Trebuchet MS',Helvetica,sans-serif; vertical-align: sub;">2 <span style="color: #800080; font-family: 'Trebuchet MS',Helvetica,sans-serif;">. Thus, NH <span style="color: #800080; font-family: 'Trebuchet MS',Helvetica,sans-serif; vertical-align: sub;">3 <span style="color: #800080; font-family: 'Trebuchet MS',Helvetica,sans-serif;"> has been oxidised. CuO is the oxidising agent.

<span style="color: #ff00ff; font-family: 'Trebuchet MS',Helvetica,sans-serif;">Let's move on to Definition 3.