Question

Sequence of acidic character is

• A. $ N_{2}O_{5} > SO_{2} > CO > CO_{2} $
• B. $ N_{2}O_{5} > SO_{2} > CO_{2} > CO $
• C. $ SO_{2} > CO_{2} > CO > N_{2}O_{5} $
• D. $ SO_{2} > N_{2}O_{5} > CO > CO_{2} $

Answer 1

Answer: (B)

Acidic nature of oxide $\propto$ Number of electron outermost shell
$\propto \frac{1}{\text { atomic size }}$
$\propto$ electronegative character
In a period from left to right the acidic nature of oxide of element increases. Therefore, $N _{2} O _{5}$ is more acidic than $CO _{2}$. Further, when the oxidation number increases, the acidic character is also increases. Hence, $CO _{2}$ is more acidic than $CO$.
In a group acidic nature of oxides decreases. So, $SO _{2}$ is more acidic than $CO _{2}$ but less than $N _{2} O _{5}$. Therefore, the correct order of acidic character is as
$N _{2} O _{5}> SO _{2}> CO _{2}> CO$