Find ΔH° for the reaction C₃H₈(g)+ 5 O₂(g)→ 3 CO₂(g)+ 4 H₂O(l). ΔH° = -2046 kJ for the reaction: C₃H₈(g)+ 5 O₂(g)→ 3 CO₂(g)+ 4 H₂O(g) The heat of vaporization of water is 44.0 kJ/mol.Note that H₂O is a liquid in the first reaction and a gas in the second.

Question

Quizplus · Accepted Answer

The difference in ΔH° between the two reactions is due to the phase change of water from gas to liquid. Since 4 moles of water are involved and the heat of vaporization is 44.0 kJ/mol, the total energy change due to condensation is 4 mol * 44.0 kJ/mol = 176 kJ. To find the ΔH° for the first reaction, subtract this energy from the ΔH° of the second reaction: -2046 kJ - 176 kJ = -2222 kJ.

Find ΔH° for the Reaction C3H8(g)+ 5 O2(g)→ 3 CO2(g)

Find ΔH° for the Reaction C₃H₈(g)+ 5 O₂(g)→ 3 CO₂(g)