Diketahui reaksi berikut ini: CO2 → C + O2 ∆H = +94 Kkal H2 + ½ O2 → H2O ∆H = -68 Kkal 2C + 3H2 → C2H6 ∆H = -20 Kkal Berapa ∆H rekasi dibawah ini? 2C2H6 + 7O2 → 4CO2 + 6H2O
Jawaban:
(grafit) + 1/2O2(g) → CO(g) ΔH = -110,54 kJ/mol (dibalikkan)
C(grafit) + O2(g) → CO2(g) ΔH = -393,51 kJ/mol (tetap)
CO(g) → C(grafit) + 1/2O2(g) ΔH = +110,54 kJ/mol
C(grafit) + O2(g) → CO2(g) ΔH = -393,51 kJ/mol
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CO(g) + 1/2O2(g) → CO2(g) ΔH = +110,54 – 393,51 = -282,97 kJ/mol