The element which on burning in air gives peroxide is

Question

The element which on burning in air gives peroxide is (A) lithium (B) sodium (C) rubidium (D) caesium

Tardigrade Admin · Accepted Answer

Alkali metals on burning in air give monoxide, peroxide or superoxide
Li forms monoxide

2 L i + \frac{1}{2} O_{2} \to L i_{2} O

Na form peroxide as well as monoxide

2 N a + O_{2} \to N a_{2} O_{2}

2 N a + \frac{1}{2} O_{2} \to N a_{2} O

K

,

R b

,and

C s

form superodxide

M (= K, R b, C s) + O_{2} \to M O_{2}

Q. The element which on burning in air gives peroxide is