The entropy versus temperature plot for phases α and β at 1 bar pressure is given. S T and S 0 are entropies of the phases at temperatures T and 0 K , respectively. C p , β - C p , α = 1 J mol

Question

The entropy versus temperature plot for phases $α$ and $β$ at 1 bar pressure is given. $S_{T}$ and $S_{0}$ are entropies of the phases at temperatures T and 0 K , respectively.

C $_{p, β}$ - C $_{p, α}$ = 1 J mol⁻¹ K⁻¹. Assume (C $_{p, β}$ - C $_{p, α}$ ) is independent of temperature in the range of 200 to 700 K. C $_{p, α}$ and C $_{p, β}$ are heat capacities of $α$ and $β$ phases, respectively.

The value of enthalpy change, $Δ H_{β} - Δ H_{α}$ (in J mol⁻¹), at 200 K is __.

TestHub · Accepted Answer

( H β ​ − H α ​ ) 400 ​ = ( H β ​ − H α ​ ) 200 ​ + 1 × 200 ​ 1.5 × 400 = Δ H + 1 × 200 ​ ​ Δ H = 400 J / mol

Chemistry - Thermodynamics - I Question with Solution | TestHub

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