The ionization enthalpy of `He^(+)` ion is `19.60 xx 10^(-18)` J `"atom"^(-1)` The ionization enthalpy of `Li^(+2)` ion will be.

Options

A. `84.2xx 10^(-18) J "atom"^(-1)`
B. `44xx 10^(-18) J "atom"^(-1)`
C. `63.20 xx 10^(-18) J "atom"^(-1)`
D. `21.20 xx 10^(-18) J "atom"^(-1)`

Answer

B

Explanation

Given : Ionisation enthalpy of
`He^(+) = 19.6 xx 10^(-18) J "atom"^(-1)`
Ionisation ethaply of `Li^(2+)` =
Ionisation enthalpy of `He^(+) xx (9)/(4) = 19.6 xx 10^(-18) (9)/(4) = 44.1 xx 10^(-18) J "atom"^(-1)`