Bond dissociation energy of E-H bond of the "" hydrides of group 16 elements (given below), follows order.
(A) O
(B) S
(C) Se
(D) Te
(A) O
(B) S
(C) Se
(D) Te
- (A)A B C D✓ Correct
- (B)A B D C
- (C)B A C D
- (D)D C B A
Answer: (A)
Solution
Descending group 16 from oxygen to tellurium the atoms grow steadily larger, the element–hydrogen bond lengthens, and the shared pair is held less firmly. A longer, weaker bond needs less energy to break, so the bond dissociation enthalpy of the E–H bond falls as the size increases. The bonds weaken in the order , that is .
JEE Main · 2023 · 30 Jan 2023 · Shift 2 · Single correct option