Lecture Review Question

[Nicole Huang 3F]

In the third question in today's lecture (the PCl3, Cl2, PCl5 one) we needed to find the partial pressures given the temperature and equation, and Dr. Lavelle used the deltaGnaught = RTlnK equation to figure it out, but I was wondering if it is still possible to solve if the question was left at the beginning (without him leading us to the deltaG of formation, given that you had no other information?

[Lucy_Balish_3G]

I couldn't think of any way to solve it unless we are given more information. We either need values for the enthalpy and entropy or the values for Gibbs free energy of formation for the products and reactants. Depending on what we are given, we take one of those approaches to the problem.

[shevanti_kumar_1E]

For that question we needed the value of delta G of reaction to get the value of the equilibrium constant K. We would also be able to solve the problem if delta H and delta S of the reaction were given. We would use dG=dH-TdS to solve for delta G.