Question

What is the correct order of acidic strength of oxides of Nitrogen:
$(A){N_2}O > NO > {N_2}{O_3} > {N_2}{O_5}$
$(B){N_2}{O_3} > NO > {N_2}O > {N_2}{O_5}$
$(C){N_2}O > {N_2}{O_5} > {N_2}{O_3} > NO$
$(D){N_2}{O_5} > {N_2}{O_3} > NO > {N_2}O$

Answer 1

Hint: Nitrogen is present in the p-block of the modern periodic table. It is a highly electronegative element and hence, it is considered as a non-metal. It forms various oxides when it reacts with oxygen in different compositions. The oxides of nitrogen can be acidic, basic and neutral in nature depending on the oxidation state of nitrogen in that oxide.

Complete answer:
Nitrogen can form many oxides when it reacts with oxygen in different proportions such as:
Nitric oxide ( $NO$ )
Nitrous oxide ( ${N_2}O$ )
Dinitrogen trioxide ( ${N_2}{O_3}$ )
Nitrogen pentoxide ( ${N_2}{O_5}$ )
These nitrogen oxides can be acidic, basic and neutral in nature depending on the oxidation state of nitrogen in that oxide because as the oxidation state increases the acidic character of the oxide increases and vice versa.
So, now we will calculate the oxidation state of nitrogen in all these oxides given:
Nitric oxide ( $NO$ )
Let the oxidation state of nitrogen be x.
$x + ( - 2) = 0$
$x = + 2$

Nitrous oxide ( ${N_2}O$ )
Let the oxidation state of nitrogen be x.
$2x + ( - 2) = 0$
On solving, we get
$x = + 1$

Dinitrogen trioxide ( ${N_2}{O_3}$ )
Let the oxidation state of nitrogen be x.
$2x + 3( - 2) = 0$
On solving, we get
$x = + 3$

Nitrogen pentoxide ( ${N_2}{O_5}$ )
Let the oxidation state of nitrogen be x.
$2x + 5( - 2) = 0$
On solving, we get
$x = + 5$
So, as we know that greater the oxidation state of nitrogen, more will be its acidic strength.
Hence, the correct order of acidic strength of oxides of nitrogen is:
${N_2}{O_5} > {N_2}{O_3} > NO > {N_2}O$

So, the correct answer is “Option D”.

Note:
We know that nitrogen is present in the p-block of the modern periodic table and has high electronegativity. It is considered non-metal. Now, we know that non-metal oxides are acidic in nature. But some oxides of nitrogen are neutral in nature such as Nitric oxide ( $NO$ ) and Nitrous oxide ( ${N_2}O$ ).