An alkali metal M on combustion in excess oxygen forms a major product X which is paramagnetic. X reacts with water to form a base Y , a compound Z , and a diatomic gas W . The sum of the atomicity (total number of atoms per molecule) of X , Y , Z , and W is ______

Step-by-step solution

Alkali metals like K, Rb, and Cs react with excess oxygen to form superoxides as the major product. Superoxides contain the O ₂^- ion, which has an unpaired electron and is paramagnetic. Thus, X is a superoxide with the formula M O ₂ . The atomicity of X ( M O ₂ ) is 1 + 2 = 3 . The hydrolysis of a superoxide proceeds as follows: 2M O ₂ + 2 H ₂ O 2M OH + H ₂ O ₂ + O ₂ From the products, Y is the base M OH , Z is hydrogen peroxide ( H ₂ O ₂ ), and W is the diatomic gas oxygen ( O ₂ ). Calculating the atomicity of ea