JEE Main 2013 Chemistry question

Chemistry Classification of Elements and Periodicity in Properties JEE Main 2013

The first ionisation potential of Na is 5.1 eV. The value of electron gain enthalpy of will be :

(1)-10.2 eV
(2)+2.55 eV
(3)-2.55 eV
(4)-5.1 eVCorrect

Answer: (4)

Solution

Adding an electron to is the reverse of ionising Na, so its electron gain enthalpy is −5.1 eV, option (4).

Question ID VK-103840