Periodic Table and PeriodicityhardMCQ SINGLE⭐ Must-Do

The electron affinity of a hypothetical element is . How much total energy (in ) is released when exPeriodic Table and Periodicity Chemistry Question

Question

The electron affinity of a hypothetical element is $-3.0 \text{ eV/atom}$. How much total energy (in $\text{kcal}$) is released when exactly 10 grams of this element ($Molar Mass = 30 \text{ g/mol}$) are completely converted to gaseous anions? (Given $1 \text{ eV} \approx 23 \text{ kcal/mol}$)

Answer: A

💡 Solution & Explanation

Energy per mole $= 3.0 \text{ eV} \times 23 \text{ kcal/eV} = 69 \text{ kcal/mol}$. Moles $= 10\text{g} / 30\text{g/mol} = 1/3 \text{ mole}$. Total energy released $= 69 \times (1/3) = 23 \text{ kcal}$.

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