Using equipartition of energy, the specific heat (in J kg ⁻¹ K ⁻¹) of aluminium at room temperature can be estimated to be (atomic weight of aluminium = 27) (a) 25 (b) 410 (c) 925 (d) 1850

Answer: (c). Solid: each atom has 3 vibrational modes, each with energy kBT, so U = 3RT per mole and C = 3R (Dulong–Petit). C = 3 × 8.31 ≈ 25 J/mol K Per kg: c = (25)/(0.027) ≈ 925 J kg ⁻¹ K ⁻¹ So the answer is (c) 925.

Using equipartition of energy, the specific heat (in J kg ⁻¹ K ⁻¹) of… | JEE Main 2015 (11 Apr, Shift 1)

Q57JEE Main 2015 · 11 APR · SHIFT 1Difficult

Specific Heats of Gases - Cp, Cv, γ & Mayer's Relation

Using equipartition of energy, the specific heat (in J kg ${}^{-1}$ K ${}^{-1}$ ) of aluminium at room temperature can be estimated to be (atomic weight of aluminium = 27)

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Answer: (c)

Solid: each atom has 3 vibrational modes, each with energy $k_BT$ , so $U = 3RT$ per mole and $C = 3R$ (Dulong–Petit).
$C = 3 \times 8.31 \approx 25$ J/mol K
Per kg: $c = \dfrac{25}{0.027} \approx 925$ J kg $^{-1}$ K $^{-1}$
So the answer is (c) 925.

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