Question

Among the following oxides, the least acidic is

• A. $P_4O_6$
• B. $P_4O_{10}$
• C. $As_40_6$
• D. $As_4Ok$

Answer 1

Answer: (C)

$As_40_6$

Answer 2

Acidic character of oxides decreases down the group. Thus, oxides of As are less acidic than those of P. Acidic character increases with increase in oxidation state. Thus $AS_4O_{10}$ (O.S. = 5) is more acidic than $As_4O_6$ (O.S. = 3). Thus $As_4O_6$ is least acidic