### How do you determine comfort in the outdoors?

Both enthalpy and entropy are factored in to determine whether a process is spontaneous or nonspontaneous, that is whether the conditions are favorable or not. Enthalpy is heat energy, while entropy measures the amount of disorder or lack of organization. You can remember that enthalpy is H and entropy is S.

You are in the middle of forest looking for a place to shelter. One environment has lots of plants undergoing photosynthesis with few animals undergoing cellular respiration. The other has few plants undergoing photosynthesis with lots of animals undergoing cellular respiration. Remember that photosynthesis absorbs energy and cellular respiration releases energy.

### Creative Applications

1. Which one would you choose to help you create a shelter and survive? Why?

2. Which of the environments is the more spontaneous?

3. For the environment with lots of plants and few animals, the temperature is 290 Kelvin, \begin{align*}\triangle\end{align*}S is 20, and \begin{align*}\triangle\end{align*}H is 6000 J. Using the formula △G = △H - T△S, calculate △G, the change in free energy.

4. For the environment with lots of animals and few plants, the temperature is 290 Kelvin, \begin{align*}\triangle\end{align*}S is 20, and \begin{align*}\triangle\end{align*}H is -6000 J. Using the formula △G = △H - T△S, calculate △G, the change in free energy.

5. Compare the answers in questions 3 and 4, what can you conclude about the two different environments?