Consider the following endothermic reaction of gaseous AB3 molecules with A2 molecules.

Identify the true statement about the spontaneity of the reaction. (a) The reaction is likely to be spontaneous at high temperatures. (b) The reaction is likely to be spontaneous at high temperatures. (c) The reaction is always spontaneous. (d) The reaction is always spontaneous.

Video transcript

Hello everyone today. We have the following problem. The gas phase decomposition of a X up, three molecules to a sub two and X up to molecules is an endo thermic reaction. The reaction is depicted in the diagram below which of the following statement is true regarding the spontaneity of the reaction. So as indicated in the question stem, this is an endo thermic reaction, which means our change in our entropy is going to be positive as we are adding energy to Are we adding heat energy into the reaction Furthermore on the reaction side, we see that we have six gas molecules, Whereas in the product side we see that we have molecules. So not only is our entropy positive, but we are increasing the disorder of our system, meaning that our entropy change is also going to be positive. The fact that we have both a positive entropy and a positive entropy means that a reaction is going to be spontaneous at high temperatures, meaning the correct answer is going to be see the reaction will be spontaneous at high temperatures and with that we've answered the question overall, I hope this helped and until next time.