Question

Which of the following oxides is not expected to react with sodium hydroxide?

• A. $BeO$
• B. $B_2{O}_3$
• C. $CaO$
• D. $Si{O}_2$

Answer 1

Answer: (C)

$CaO$

$CaO$ is not expected to react with $NaOH$ because $NaOH$ is a base and it can only react with either an acidic oxide or an amphoteric oxide.

Among given options $BeO$ is an amphoteric oxide while $B_2{O}_3$ and $Si{O}_2$ are acidic oxides.Thus, all of them react with $NaOH$ to form salts.

$CaO$, on the other hand, is a basic oxide and hence it will not react with $NaOH$.