- Optional filter -
Hello, I had my AP Chemistry midterm recently, and there was one question that seemed actually impossible. It probably isn't, and I wanted to see if any of you could solve it. (It seemed like it was impossible to combine the two last equations into the first.) This is the question.
Use Hess' Law to calculate the enthalpy of this reaction in kJ/mol:
4PCl3 => P4 + 6Cl2
Use these two equations and their respective enthalpies:
4PCl5 => P4 + 10Cl2 (1528 kJ/mol)
PCl3 + Cl2 => PCl5 (-111 kJ/mol)