The molar heat capacity at should be close to 27 J/K-mol for all of the given elements except — Thermodynamics and Thermochemistry Chemistry Question

💡 Solution & Explanation

By the Dulong-Petit law, the molar heat capacity of solid elements is approximately $3R \approx 25\text{ J/K-mol}$. Neon (Ne) is a monoatomic gas at room temperature, not a solid, and thus has a molar heat capacity of strictly $5/2 R$ or $3/2 R$, making it the exception.