Classification Of Elements And Periodicity In Properties Ques 119
Question: Which one of the following arrangements represents the correct order of electron gain enthalpy (with negative sign) of the given atomic species. [CBSE PMT 2005]
Options:
A) $ O<S<F<Cl $
B) $ Cl<F<S<O $
C) $ S<O<Cl<F $
D) $ F<Cl<O<S $
Show Answer
Answer:
Correct Answer: B
Solution:
Halogens have very high electron affinity. It may be rated that the electron affinity of fluorine is unexpectedly low $ (<Cl) $ . This may perhaps be due to small size of F atom. The value of electron gain enthalpies for $ Cl,F,S $ and O are respectively 349, 333, 200 & 142 KJ / mol hence correct order is $ Cl>F>S>O $
