2 ZnS (s sphalerite) + 2 H2SO4 (aq) + 1 O2 (g) → 2 ZnSO4 (aq) + 2 S (s rhombic) + 2 H2O (ℓ)

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Stoichiometry

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ZnS            Mass: g
H2SO4          Mass: g  or Solution Volume: mL of Concentration: mol/L
O2             Mass: g  or Gas Volume: L
ZnSO4          Mass: g
S              Mass: g
H2O            Mass: g
Heat Released: kJ

Enthalpy of Reaction

[2ΔHf(ZnSO4 (aq)) + 2ΔHf(S (s rhombic)) + 2ΔHf(H2O (ℓ))] - [2ΔHf(ZnS (s sphalerite)) + 2ΔHf(H2SO4 (aq)) + 1ΔHf(O2 (g))]
[2(-1063.17) + 2(0) + 2(-285.83)] - [2(-205.98) + 2(-909.27) + 1(0)] = -467.5 kJ
-467.50 kJ     (exothermic)

Entropy Change

[2ΔSf(ZnSO4 (aq)) + 2ΔSf(S (s rhombic)) + 2ΔSf(H2O (ℓ))] - [2ΔSf(ZnS (s sphalerite)) + 2ΔSf(H2SO4 (aq)) + 1ΔSf(O2 (g))]
[2(-92.02) + 2(31.92) + 2(69.91)] - [2(57.74) + 2(20.08) + 1(205.03)] = -341.05 J/K
-341.05 J/K     (decrease in entropy)

Free Energy of Reaction (at 298.15 K)

From ΔGf° values:
[2ΔGf(ZnSO4 (aq)) + 2ΔGf(S (s rhombic)) + 2ΔGf(H2O (ℓ))] - [2ΔGf(ZnS (s sphalerite)) + 2ΔGf(H2SO4 (aq)) + 1ΔGf(O2 (g))]
[2(-891.73) + 2(0) + 2(-237.18)] - [2(-201.29) + 2(-744.63) + 1(0)] = -365.98 kJ
-365.98 kJ     (spontaneous)

From ΔG = ΔH - TΔS:
-365.82 kJ     (spontaneous)

Equilibrium Constant, K (at 298.15 K)

1.31974391e+064
This process is favorable at 25°C.

Reference(s):

Swaddle, T.W. Inorganic Chemistry; Academic Press: San Diego, 1997; p 360.

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