Question

Electron affinity is expressed in
a) kJ
b) J
c) kJ mol
d) kJ mol-1

Answer 1

Answer ⇒ Option (d). kJ mol⁻¹

Electron affinity is measured in the unit kJ mol⁻¹.

Explanation ⇒ 
Electron affinity is the amount of the energy released while converting the neutral isolated gaseous atom into the negatively charged ions. 

The electron affinity is measured per mole. Hence, the amount of the energy released per mole is called as the Electron affinity. 
Hence, the SI. Unit of the Electron enthalpy is kJ/mole⁻¹.

Thus, Option d. is correct. 

Hope it helps.

Answer 2

Answer ⇒ Option (d). kJ mol⁻¹

Electron affinity is measured in the unit kJ mol⁻¹.