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
H2S(g) + Cl2(g) → 2HCl(g) + S(s)
H2S loses hydrogen to form S. Thus, H2S has been oxidised. Cl2 is the oxidising agent.
Example 2
2NH3 + 3CuO → N2 + 3Cu + 3H2O
NH3 loses hydrogen to form N2. Thus, NH3 has been oxidised. CuO is the oxidising agent.
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
H2S(g) + Cl2(g) → 2HCl(g) + S(s)
H2S loses hydrogen to form S. Thus, H2S has been oxidised. Cl2 is the oxidising agent.
Example 2
2NH3 + 3CuO → N2 + 3Cu + 3H2O
NH3 loses hydrogen to form N2. Thus, NH3 has been oxidised. CuO is the oxidising agent.
Let's move on to Definition 3.