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### Higher Molar Entropy

Posted: Sun Feb 04, 2018 10:35 pm
How would you define molar entropy? What are some good ways to determine if a substance or compound has a higher or lower molar entropy?

### Re: Higher Molar Entropy

Posted: Sun Feb 04, 2018 10:46 pm
A good way to define molar entropy is just the amount of entropy in one mole of the given substance. Although it's important to remember that when it's mentioned, it's usually referred to as "standard molar entropy," meaning that it's asking for the molar entropy at standard conditions.

The numbers for standard molar entropies are given in the back of the textbook, but a general rule of thumb is to know that standard molar entropies increase as the complexity of the substance increases. A gas is going to have a higher standard molar entropy than a liquid or a solid, etc.

### Re: Higher Molar Entropy

Posted: Sun Feb 04, 2018 11:36 pm
Molar entropy is the amount of entropy change resulting from the formation of one mol of its substance from its simplest/purest components. It can be calculated using the molar entropy values of other components in an equation. The more disordered a phase is the more entropy. Gasses have the most and solids have the least.

### Re: Higher Molar Entropy

Posted: Sun Feb 04, 2018 11:44 pm
Also, a more massive element would have a higher molar entropy because there are fundamental particles (electrons, protons, neutrons), and so would a molecule made up of multiple atoms vs. one atom.

### Re: Higher Molar Entropy

Posted: Sun Feb 04, 2018 11:57 pm
Entropy values are given as standard molar entropy which is the entropy of one molecule of a substance as standard state conditions. The standard molar entropy of any substance increases as the temperature increases.