Which of the following redox reaction is a displacement reaction ?

Options

A. `N_2(g) + O_2(g) rarr 2NO(g)`
B. `2Pb(NO_3)_2(s) rarr 2PbO(s) +2NO_2(g) + 1/2 O_2 (g)`
C. `NaH(s) + H_2O(l) rarr NaOH(aq.) + H_2(g)`
D. `2NO_2(g) +2 HO^(-) (aq.) rarr NO_2^(-) (aq) + NO_3^(-) (aq.) +H_2(l)`.

Answer

C

Explanation

In reaction (1), the compound nitric oxide is formed by the combination of the elemental substances, nitrogen and oxygen. Therefore, it is an example of combination redox reaction. Reaction (2) involves the breaking down of lead nitrate into three components. Therefore, this is categorized under decomposition redox reaction. In reaction (3), hydrogen of water has been displaced by hydride ion to yield dihyrogen gas. Therefore, this may be called as displacement redox reaction. Reaction (4) involves the disproprtionation of `NO_2` (+4 state) into `NO_2^(-)` (+3 state) and ` NO_3^(-)` (+5 state). Therefore. reaction (4) is an example of disproportionation redox reaction.