1. In your own words... and in at least a couple of sentences... What is the chemical potential? Give a physical example of two systems which are in thermal equilibrium but which have different chemical potentials.
What do you think is the physical significance of a negative chemical potential? Can you think of a case when a system might have a negative chemical potential?
Enter your answer here:
2. If you assume the atmosphere is isothermal, you can use the idea of chemical potential to show how atmospheric pressure varies with altitude. Assume each gas species is characterized by its own mass.* At about what height would the pressure due to nitrogen reach half its sea level value?
What about for hydrogen gas? At what height would hydrogen's pressure be half its sea level value?
(State any assumptions you make/values you use.)
*Note: FYI, really, in our atmosphere, "atmospheric mixing" jumbles up all the gas constituents of the atmosphere in the first 100 km or so of the atmosphere. This means that each gas species "falls off" with altitude about the same way, as if characterized by the mass of a "typical air molecule" rather than its particular species mass.
3. Which of the following is true?
Check the correct answer: a) The specific value of a system's chemical potential has physical significance, as does the difference between two systems' chemical potentials.b) Only differences in chemical potentials matter.c) The zero level of chemical potential determines the direction of particle flow from one system to another.d) Two systems with different chemical potentials but the same temperature can be in diffusive equilibrium, but only if they are in an external field. Below is a space for your thoughts, including general comments about today's assignment (what seemed impossible, what reading didn't make sense, what we should spend class time on, what was "cool", etc.): You may change your mind as often as you wish. When you are satisfied with your responses click the SUBMIT button.
I received no help from anyone on this assignment. I received help from someone on this assignment (document in comments section).