The bond dissociation energies for `Cl_(2), I _(2)`and ICI are 242.3, 151 and 211.3 kJ/mol respectively. The enthalpy of sublimation of iodine is 62.8 kJ/mol. What is the standard enthalpy of formation of ICI (g)?

Options

A. `-211.3` kJ/mol
B. `-14.6` kJ/mol
C. 16.8 kJ/mol
D. 33.5 kJ/mol

Explanation

`Cl _(2) (g) to 2 Cl (g)," " Delta H _(1) = 242. 3 kJ // mol`
`I _(2) (g) to 2 I (g), " " Delta H _(2) = 151 kJ // mol`
`ICl (g) to I (g) + Cl (g) , " " Delta H _(3) -= 211. 3 kJ // mol`
`I _(2) (s) to I _(2) (g)," " Delta H _(4) = 628 kJ // mol`
Required equation `(1)/(2) I _(2) (s) + (1)/(2) Cl _(2) (g) to ICl (g) , Delta H = ? Delta H = (62.8 + 151 + 242. 3)/(2) - 211.3 = 16. 75 `kJ/mol