The compound which does not exist is (A) NaO2 (B) (NH4)2BeF4 (C) BeH2 (D) PbEt4 — JEE Mains Chemistry Past Papers Chemistry Question

💡 Solution & Explanation

Alkali metals generally form oxides and peroxides. M+O2 M2O (Oxide) M2O2 (Peroxide) The alkali metals tarnish in dry air due to the formation of their oxides on their surface. 4M + O2 — 2M2O They react vigorously in oxygen forming following oxides. 4 Li + O2 — 2 Li2O (Monoxide) 2 Na + O2 — Na2O2 (Peroxide) M + O2 — MO2 ( Superoxide) where M = K, Rb, Cs Principal Combustion Product (Minor Product) Metal Oxide Peroxide Superoxide Li Li2O (Li2O2) Na (Na2O) Na2O2 K KO2(Orange/Yellow Crystalline) Rb RbO2 (Orange/Yellow Crystalline) Cs CsO2 (Orange/Yellow Crystalline)