The enthalpy changes for the following process are listed below :
`Cl_(2)(g)=2Cl(g),” “242.3” kJ”mol^(-1)`
`I_(2)(g)=2I(g),” “151.0” kJ”mol^(-1)`
`ICl(g)=2I(g)+Cl(g),” “211.3” kJ”mol^(-1)`
`I_(2)(s)=I_(2)(g),” “62.76” kJ”mol^(-1)`
Given that standard states for iodine and chlorine are `I_(2)(s)` and `Cl_(2)(g)`, the standerd enthalpy of formation for ICl(g) is :
A. `-16.8 KJ mol^(-1)`
B. `+16.8 KJ mol^(-1)`
C. `+244.8 KJ mol^(-1)`
D. `-14.6 KJ mol^(-1)`
`Cl_(2)(g)=2Cl(g),” “242.3” kJ”mol^(-1)`
`I_(2)(g)=2I(g),” “151.0” kJ”mol^(-1)`
`ICl(g)=2I(g)+Cl(g),” “211.3” kJ”mol^(-1)`
`I_(2)(s)=I_(2)(g),” “62.76” kJ”mol^(-1)`
Given that standard states for iodine and chlorine are `I_(2)(s)` and `Cl_(2)(g)`, the standerd enthalpy of formation for ICl(g) is :
A. `-16.8 KJ mol^(-1)`
B. `+16.8 KJ mol^(-1)`
C. `+244.8 KJ mol^(-1)`
D. `-14.6 KJ mol^(-1)`
Correct Answer – B
`(1)/(2) I_(2)(s) + (1)/(2) CI_(2)(g) rarr ICI(g)`
`DeltaH_(f,ICI) (g) = [(1)/(2)DeltaH_(I_(2))(s) rarr I_(2)(g) + (1)/(2)DeltaH_(I-I) + (1)/(2)Delta_(CI-CI)] – [DeltaH_(I-CI)]`
`=[(1)/(2)xx 62.76 + (1)/(2)151.0 + (1)/(2)xx 242.3] -[211.3]=16.73 KJ//mol`