Question

Methanol burns in oxygen to form carbon dioxide and water. part a write a balanced equation for the combustion of methanol. write a balanced equation for the combustion of methanol. ch3oh(l)+3o2(g)→co2(g)+3h2o(g) ch3oh(l)+o2(g)→co2(g)+2h2o(g) ch3oh(l)+2o2(g)→2co2(g)+4h2o(g) 2ch3oh(l)+3o2(g)→2co2(g)+4h2o(g) submitmy answersgive up part b calculate δh∘rxn at 25 ∘c. δh∘rxn = kj submitmy answersgive up part c calculate δs∘rxn at 25 ∘c. δs∘rxn = j/k submitmy answersgive up part d calculate δg∘rxn at 25 ∘c.

Answer 1

Part a)
Balanced equation:
2 CH₃OH(l) + 3 O₂(g) → 2 CO₂(g) + 4 H₂O(g)
Part b)
ΔH for the reaction at 25°C
ΔH = Enthalpy change of products - Enthalpy change of reactants
      = [(2 mol) * (-393.509 kJ/mol) + (4 mol)*(-241.83 kJ/mol)] - [(2 mol) * (238.4 kJ/mol) + (3 mol) *(0 kJ/mol)] = - 1277.5 kJ
Part c)
ΔS for the reaction at 25°C 
ΔS = entropy change in products - entropy change in reactants
     = [(2 x 213.7) + (4 x 188.8)] - [(2 x 127.2) + (3 x 205.1)] = 312.9 J K⁻¹
Part d)
ΔG for the reaction at 25°C
ΔG = ΔH - (T * ΔS)
     = - 1277.5 x 10³ J - (298 x 312.9 J K⁻¹) = -1370.7 kJ