Question

Bond energy is related to bond length. Use the bond energy data below to arrange the bonds listed in order of increasing bond length (shortest to longest).Bond : Energy (kJ/mol)
- C-C : 346
- C=C : 835
- C≡C : 612

Answer 1

Answer:

The order of increasing bond lenght :

-C≡C < -C=C < -C-C

Explanation:

Bond length is defined as average distance between two nuclei of  bonded atoms in a molecule.Bond length is inversely  proportional to the number of bonds present between two atoms.

$\text{Bond length} \propto \frac{1}{\text{Number of bonds}}$...[1]

Bond energy is defied as amount of energy required to break apart the bond of 1 mole of molecule into their individual atom.

Bond energy is directly proportional to the number of bonds present between two atoms.

$\text{Bond Energy} \propto \text{Number of bonds}$..[2]

From [1] and [2]:

$\text{Bond length} \propto \frac{1}{\text{Bond energy}}$

Bond : Energy (kJ/mol)

-C-C : 346

-C=C : 612

-C≡C : 835

The order of decreasing bond energy :

835 kJ/mol   > 612 kJ/mol > 346  kJ/mol

The order of increasing bond lenght :

-C≡C < -C=C < -C-C