Question

2 attempts left Check my work Be sure to answer all parts. Using the periodic table only, arrange the members of each of the following sets in order of increasing bond strength: (select) (a) Br-Br, Cl-CI, I-I (select) (b) S-H, S-Br, S-CI

Answer 1

(a) As we move from Cl to I, the atomic size increases. It means the size of valence orbital increases and thus bond formed by that orbitals will increase from Cl to Br. Thus, bond length increases from Cl₂ to I₂ . Greater the bond length, more easy to break that bond, lower the bond energy and hence lower will be the strength of bond.

Order of strength of bond: Cl₂ > Br₂ > I₂

(b) Since all bonds contain S atom. So bond length will depend upon the size of other atoms.

Since atomic size order: H < Cl < Br

Bond length order : SH < SCl < SBr

Greater the bond length, lower will be the strength.

Thus order of strength : SH > SCl > SBr.