The bond dissociation energies for `Cl_(2)`, `I_(2)` and `IC l` are `242.3`, `151.0` and `211.3 kJ//"mole"` respectively. The enthalpy of sublimation of iodine is `62.8 kJ //"mole"`. What is the standard enthalpy of formation of `ICI(g)` nearly equal to

Options

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

Answer

C

Explanation

`Cl_(2)(g)to2Cl(g)," "H_(1)=242.3kJ//mol`
`I_(2)(g)to2I(g)," "DeltaH_(2)=151kJ//mol`
`"ICl(g)"toI(g)+Cl(g)," "DeltaH_(3)=211.3kJ//mol`
`I_(2)(s)toI_(2)(g)," "DeltaH_(4)=62.8kJ//mol`
`(1)/(2)I_(2)(s)+(1)/(2)Cl_(2)(g)toI Cl(g)," "DeltaH=?`
`DeltaH=(62.8+151+242.3)/(2)-211.3`
`=16.75kJ//mol`