The first ionisation potential of `Na` is `5.1eV`. The value of eectrons gain enthalpy of `Na^(+)` will be

Options

A. `-2.55 eV`
B. `-5.1 eV`
C. `-10.2 eV`
D. `+2.55 eV`

Answer

B

Explanation

`Na to Na^(+) + e^(-) ` First IE , `Na^(+) + e^(-) to Na ` Electron Gain Enthalpy The electron gain enthalpy will be the reverse of I.E. since the reaction is also the reverse.