Which is the correct thermal stability order of `H_(2)E(E=O,S,Se,Te` and `Po)`?

Question

Which is the correct thermal stability order of H 2 E ( E = O , S , S e , T e H and P o ) P ? A. H 2 S e < H 2 T e < H 2 P o < H 2 O < H 2 S H B. H 2 S < H 2 O < H 2 S e < H 2 T e < H 2 P o H C. H 2 O < H 2 S < H 2 S e < H 2 T e < H 2 P o H D. H 2 P o < H 2 T e < H 2 S e < H 2 S < H 2 O H Select the correct answer from above options

Answer 1

Correct Answer - D In oxygen family down the group thermal stability decreases order of thermal stability H 2 O > H 2 S > H 2 S e > H 2 T > H 2 P o H ] this is because M-H bond dissociation energy decrease down the group with the increase in the size of central atom.