Which of the following arrangements represents the correct order of electron gain enthalpy?
A.
$$O < S < F < Cl$$
B.
$$Cl < F < S < O$$
C.
$$S < O < Cl < F$$
D.
$$F < Cl < O < S$$
Answer :
$$O < S < F < Cl$$
Solution :
Electron gain enthalpy becomes more negative across a period while it becomes less negative in a group. However, electron gain enthalpy of $$O$$ or $$F$$ is less than that of the succeeding element. When electron is added to $$n =2,$$ the repulsion is more than when it is added to $$n=3$$ in case of $$Cl$$ or $$S.$$
Releted MCQ Question on Inorganic Chemistry >> Classification of Elements and Periodicity in Properties
Releted Question 1
The correct order of second ionisation potential of carbon, nitrogen, oxygen and fluorine is