From the following data, calculate the enthalpy changc for the combustion of cyclopropane at 298 K. The enthalpy of formation of CO 2(g), H 2 O (l) and propane (g) are -393.5, -285.8 and 20.42 kJ mol -1 respectively. The enthalpy of isomerisation of cyclopropane to propene is -33.0 kJ mol -1.

Question

From the following data, calculate the enthalpy changc for the combustion of cyclopropane at 298 K. The enthalpy of formation of CO 2(g), H 2 O (l) and propane (g) are -393.5, -285.8 and 20.42 kJ mol -1 respectively. The enthalpy of isomerisation of cyclopropane to propene is -33.0 kJ mol -1. (A)  (B)  (C)  (D)

Tardigrade Admin · Accepted Answer

Given: Cyclopropane longrightarrow Propene ( C 3 H 6) ; Δ H=-33 kJ Propene ( C 3 H 6)+(9/2) O 2 longrightarrow 3 CO 2(g)+3 H 2 O (l) Δ H=-3(393.5+285.8)-20.42=-2058.32 kJ Adding: Cyclopropane +(9/2) O 2(g) longrightarrow 3 CO 2(g)+3 H 2(g) Δ H =H1+H2 =-33+(-2058.32) kJ Δ H =-2091.32 kJ

Given : Cyclopropane ⟶ Propene (C3​H6​);ΔH=−33kJ Propene (C3​H6​)+29​O2​⟶3CO2​(g)+3H2​O(l) ΔH=−3(393.5+285.8)−20.42=−2058.32kJ Adding : Cyclopropane +29​O2​(g)⟶3CO2​(g)+3H2​(g) ΔH=H1​+H2​ =−33+(−2058.32)kJ ΔH=−2091.32kJ