Question

a) 计算以下反应的摩尔焓变:CH3CH2CH3(g) +5 O2(g) ->3 CO2(g)+ 4 H2O（l)

Answer 1

a)求反应的摩尔焓变

CH3CH2CH3(g) + 5 O2(g) -> 3 CO2(g) + 4 H2O（l)

ΔrH = 3*ΔfH(CO2(g)) + 4*ΔfH(H2O(l)) - ΔfH(CH3CH2CH3(g)) - 5*ΔfH(O2(g))

= 3*(-394) + 4*(-286) - (-104) - 5*0

= - 2222 ( kJ /mol)

b)求内能变化

ΔrU = ΔrH - ΔnRT

= - 2222 - ( 3 -5-1) * 8.314 * 308 * 10^-3

= - 2214.3 ( kJ /mol)