Assuming that gaseous reactants and products are present at 1 atm partial pressure, which of the following reactions are spontaneous in the forward direction? (a) (b) (c) (d)

Video transcript

Hello everyone today. We are being asked the following question. The reactant and products in the gaseous phase for the following reactions are present at one atmosphere, partial pressure in the forward direction which reactions proceed spontaneously. So in order to analyze this, we must first analyze the relationship between the change in our Gibbs free energy and our K. P. Constant which is the constant for partial pressure. And so that is that the gibbs free energy or the change in the gibbs free energy is going to be equal to negative of the gas constant times the temperature times the natural log of R. K. P. Constant. And so we can use the following relationships. If our K. P constant is greater than zero, then naturally our natural log of R. K. P constant will be greater than zero. Which will result in our change in our gifts. Free energy being less than zero. So it's an inverse relationship. If our Gibbs free energy change is less than zero, then this reaction is going to be spontaneous. So which of these reactions is going to be spontaneous? With a positive K. P expression or K. P. Expression that's greater than our zero. We have to look for large K. P. Values. And so that's gonna be reactions to with the K. P. Value of 1.1 times 10 to the fifth. And reactions four with the K. P value of 1.3 times 10 to the negative or 1.3 times 10 to the 10th power. If we look at reactions one in three, they both have negative or very small K. P. Expressions. And so with that we've answered the question overall, I hope this helped, and until next time.