Question

Oxidising power of chlorine in aqueous solution can be determined by the parameters indicated below
`(1)/(2)CL_(2)(g)overset((1)/(2)Delta_(diss)H^(Theta))(rarr)Cl(g)overset(DeltaH_(Eg)^(Theta))(rarr)`
`Cl^(-)(g)overset(Delta_(hyd)H^(Theta))(rarr)Cl^(-)(aq)`
The energy involved in the conversion of `(1)/(2)Cl_(2)(g)` to
`Cl^(-)(aq)`
(Using the data `Delta_(diss)H_(Cl_(2))^(Theta)=240KJ mol^(-1)`)
`Delta_(Eg)H_(Cl)^(Theta)=-349KJmol^(-1)` ,
`Delta_(Eg)H_(Cl)^(Theta)=-381KJmol^(-1)`) will be
A. `-850 kJ mol^(-1)`
B. `+120 kJ mol^(-1)`
C. `+152 kJ mol^(-1)`
D. `-610 kJ mol^(-1)`

Answer 1

Correct Answer - D
For the process `(1)(2)Cl_(2)(g)toCl^(-)(aq)` using the given steps
`DeltaH=(1)/(2)Delta_(diss)H_((Cl_(2)))+Delta_(eq)H_((Cl))+Delta_(hyd)H_((Cl^(-)))`
`=(240)/(2)-349-381`
`=120-73-610 kJ mol^(-1)`