Question
Electron gain enthalpy with negative sign of fluorine is less than that of chlorine due to :
A.
High ionization enthalpy of fluorine
B.
Smaller size of chlorine atom
C.
Smaller size of fluorine atom
D.
Bigger size of $$2p$$ orbital of fluorine
Answer :
Smaller size of fluorine atom
Solution :
The electron gain enthalpy order for halogens is $$Cl > F > Br > I$$
Due to small size of fluorine the extra electron to be added feels more electron-electron repulsion. Therefore fluorine has less value for electron affinity than chlorine.