Statement-1: The decreasing order of acidic character of ${\mathrm{CO}}_2,{\mathrm{N}}_2{\mathrm{O}}_5,{\mathrm{SiO}}_2$ and ${\mathrm{SO}}_3$ is ${\mathrm{SO}}_3>{\mathrm{N}}_2{\mathrm{O}}_5>{\mathrm{CO}}_2>{\mathrm{SiO}}_2$.

Statement-2: As electronegativity difference (E-O) decreases, acidic character of the oxide increases.

The acidic nature of oxides also increases as the nonmetallic character increases over time. On the other hand, as the group gets smaller, the metallic character grows and the acidic nature of oxides decreases. Consequently, the order of acidity should be,

${\mathrm{SO}}_3>{\mathrm{N}}_2{\mathrm{O}}_5>{\mathrm{CO}}_2>{\mathrm{SiO}}_2$

The ability of an element to draw in electron pairs is known as electronegativity. Because of this drop in electronegativity, the acidity of the oxides "decreases along the group.