Question

Among halogens, the correct order of amount of energy released in electron gain (electron gain enthalpy) is:
A. FgtClgtBrgtI
B. FltClltBrltI
C. FltClgtBrgtI
D. FltClltBrgtI

Answer 1

Correct Answer - C
Electron gain enthalpy becomes less negative on moving down a group due to increase In atomic size.However,the electron gain enthalpy of F is less negative than that of Cl due to electron-electron-electron repulsion in small sized F atom.Thus,the correct order is:`Delta_(eg)H(KJ mol^(-1)): underset(-328)(F)ltunderset(-349)(Cl)gtunderset(-325)(Br)gtunderset(-295)(I)`