How does the molar entropy of a substance change with increasing temperature?

Video transcript

Welcome back everyone in this example, we need to determine the relationship of molar entropy of the substance and temperature. So recall that entropy is represented by the symbol S. And we can calculate the change in entropy of the substance by recalling that this is a measure of the random displacement of thermal energy of a substance. Or we can say of a subsystem if it's a reaction. But in this case we're comparing the molar entropy of a substance to temperature. So we want to recall that we can use the following formula where we say that our change in free energy of our substance is going to equal our entropy of our substance subtracted from the temperature multiplied by the change in entropy of that substance. And we can see that everything is in the numerator here. But specifically focusing on temperature and entropy, we see that they're directly related to one another. So we can say temperature is directly related to change in entropy of a substance. And so that would mean that therefore as temperature increases, the entropy of our substance is also going to increase. And that also as temperature decreases, the change in entropy of our substance should decrease. And that is due to the fact that the movement of the molecules making up this substance are going to go through even more displacement. So they're going to be even more randomly distributed and disordered because temperature is going to cause these molecules of our substance to move faster as temperature increases. So we can specifically say that as temperature increases molecules of a substance well speed up and there measure of entropy will increase. So for our final answer, we can confirm that as temperature increases, our entropy will also increase. So what's highlighted in yellow is our final answer. This is going to correspond to choice A in the multiple choice. If you have any questions, leave them down below, and I'll see everyone in the next practice video.