Question

The energy required to convert all atoms present in $1.2$g magnesium to $M{g}^{2+}$ ions if $IE$, and $I{E}_2$ of magnesium are $120$ kJ $mo{l}^{-1}$ and $240$ kJ $mo{l}^{-1}$ respectively.

• A. $18$ kJ
• B. $36$ kJ
• C. $360$ kJ
• D. $24$ kJ

Answer 1

The correct option is A $18$ kJ

$Mg⟶{Mg}^{+}+e^{-}\left(120kJ/mol\right)$

$\downarrow$

${Mg}^{2+}+e^{-}\left(240kJ/mol\right)$

$\therefore$Total Energy $=360$kJ/mol

For $0.05$mole Mg since mass of Mg is 1.2g

$\therefore$ Energy $=(360\times 0.05)=18kJ$