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Problem 3

State the first law of thermodynamics in terms of…


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Problem 2

Distinguish between the terms spontaneous and nonspontaneous. Can a nonspontaneous process occur? Explain.

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Video Transcript

so Chapter 20 problem, too, is asking us to distinguish between something that spontaneous shown here by the S and something that's non spontaneous shown by N S. So let's think about what it doesn't represent. When we're thinking about spontaneous or non spontaneous and chemistry. We do not care about the speed or the rate of the reaction that is not important. Whether it's fast or slow under given conditions is not a factor. What we do care about is if something is able to happen under the conditions or, if it is not ableto happen under given conditions. So something that spontaneous under given conditions does not need extra energy, so you do not have to put energy into it for it to happen. If we think about an example, we can consider an ice cube on the counter time. When you put that ice cube on the countertop, it is going to become a liquid spontaneously under the given conditions of the environment of your kitchen, or or the wherever you are, where something that's non spontaneous would be having that liquid become an ice cube. It would take energy or the removal of energy for that to occur. So when you have a spontaneous reaction or a spontaneous change, no extra energy has to be put into it. For it to happen for something that is not spontaneous, it does require energy. Let's think about a hill as an example. If we have a spontaneous reaction, we can consider a ball at the top of the hill. We know that if a ball is at the top of the hill, this ball is going to move downward. Under these given conditions of gravity on Earth, the ball is going to move down that hill, something that is non spontaneous would be the ball at the bottom of the hill. This ball is not going to move up that hill without putting energy into this system. So this would be a non spontaneous change where this could be a spontaneous change. And one thing to know that the opposite of a spontaneous change is a non spontaneous change. So if it's spontaneous going down going up, it would be non spontaneous and vice versa. So this is a way you can distinguish between something that spontaneous and not spontaneous, spontaneous and non spontaneous. Both occur. One requires no energy. The other does require energy, and if it's spontaneous in one direction, it is not spontaneous and the other.

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