Question

The main oxides formed on combustion of $Li, Na$ and $K$ in excess of air are, respectively :

• A. $Li_2O, Na_2O$ and $KO_2$
• B. $LiO_2, Na_2O_2$ and $K_2O$
• C. $Li_2O, Na_2O_2 $ and $KO_2$
• D. $Li_2O, Na_2O$ and $ KO_2$

Answer 1

Answer: (C)

The main oxides formed on combustion of $Li , Na$ and $K$ in excess of air are, respectively $Li _{2} O , Na _{2} O _{2}$ and $KO _{2}$.
Under ordinary conditions, lithium forms the monoxide, sodium forms the peroxide and other alkali metals form superoxide.