a) There are two isomers of butane: butane (C₄H₁₀) and isobutane (methylpropane) (iso-C₄H₁₀). Determine the standard enthalpy of isomerisation Δ_h^◦ of butane to isobutane in terms of the enthalpies of formation of the two isomers, h_C4H10 and h_iso-_C4H10.

b) The lunar module ‘Eagle’ of the Apollo mission was propelled using the energy released by the reaction:

Determine the molar enthalpy Δ_h◦ of this exothermic reaction in terms of the enthalpies of formation of the reactants, h_{H2NN(CH3)2(l)}, h_N2O4(l) and of the products h_N2(g) h_CO2(g), h_H2O. 

c) The combustion of acetylene (C₂H₂) is described by the chemical reaction:Determine the enthalpy of formation h_C2H2 of acetylene (C₂H₂) in terms of the molar enthalpies h_O2(g), h_CO2(g), h_H2O(g), the molar enthalpy of the reaction Δh^◦ and the vaporisation molar enthalpy of water h_vap.Numerical Application:

a)

b)

c)

Transcribed Image Text:

H₂NN(CH3)2(1) + 2N₂O4(1)→ 3N₂(g) + 2 CO₂(g) + 4H₂O(g)