Question

a. Which bond will be longer?

b. Which bond will be stronger?

1. C-Cl or C-l
2. C-C or C-l
3. H-Cl or H-F

Short answer

Compounds	Bond length	Bond strength
a. C - Cl or C - I	C - Cl < C - I	C - Cl > C - I
b. C - C or C - CI	C - C < C - CI	C - C > C - CI
c. H - CI or H - F	H - CI > H - F	H - CI < H - F

Step-by-step solution

Subpart (a) Comparing bond length.

1. As C-Cl has stronger bond compared to C-l and bond length is inversely proportional to bond strength. The order of bond length is C-Cl < C-l.
2. C-C bond is stronger than C-Cl bond thus the order of bond length is C-C < C-Cl .
3. Since H-F has a stronger bond than H-Cl and therefore H-Cl has a longer bond than H-F.

Subpart (b) Comparing the bond strength:

1. C-Cl or C-l

As the electronegativity of chlorine is greater than iodine. Therefore, C-Cl has a stronger bond compared to C-l .

2. C-C or C-Cl

Higher bond enthalpy and better overlapping makes C-C stronger than C-Cl bond.

3. H-Cl or H-F

As the electronegativity of fluorine is greater than chlorine H-F has a stronger bond than H-Cl.