The ionization enthalpy of He+ ion is 19.60 ×10-18 J atom-1. The ionization enthalpy of Li2+ ion will be

Question

The ionization enthalpy of He+ ion is 19.60 ×10-18 J atom-1. The ionization enthalpy of Li2+ ion will be (A) 84.2×10-18 J atom-1 (B) 44.10×10-18 J atom-1  (C) 63.20×10-18 J atom-1 (D) 21.20×10-18 J atom-1

Tardigrade Admin · Accepted Answer

Ionisation enthalpy propto Z2 (Z=Atomic numder) Ionisation enthalpy of Li2+=I.E. of He+×((32/22)) I.E. of Li2+=19.6×10-18×(9/4)=44.1×10-18 J atom-1

Q. The ionization enthalpy of $H e^{+} i o ni s 19.60 \times 1 0^{- 18} J a t o m^{- 1} .$ The ionization enthalpy of $L i^{2 +}$ ion will be

$84.2 \times 1 0^{- 18} J a t o m^{- 1}$

$44.10 \times 1 0^{- 18} J a t o m^{- 1}$

$63.20 \times 1 0^{- 18} J a t o m^{- 1}$

$21.20 \times 1 0^{- 18} J a t o m^{- 1}$

Ionisation enthalpy $\propto Z^{2} (Z = A t o mi c n u m d er)$
Ionisation enthalpy of $L i^{2 +} = I . E . o f H e^{+} \times (\frac{3 ^{2}}{2 ^{2}})$
$I . E . o f L i^{2 +} = 19.6 \times 1 0^{- 18} \times \frac{9}{4} = 44.1 \times 1 0^{- 18} J a t o m^{- 1}$

Q. The ionization enthalpy of He+ionis19.60×10−18Jatom−1. The ionization enthalpy of Li2+ ion will be

84.2×10−18Jatom−1

44.10×10−18Jatom−1

63.20×10−18Jatom−1

21.20×10−18Jatom−1