Question

Help please i keep going over this question over and over in my head and i cant come up with an answer.

Answer 1

Describe in detail what you know about the enthalpy, entropy, and free energy changes when a sample of gas condenses to a liquid. How does temperature affect these changes?

Answer 2

@amistre64 @myininaya @zepdrix

Answer 3

@Callisto

Answer 4

@kirbykirby @Preetha

Answer 5

Enthalpy = the amount of heat content used or released in a system at constant pressure. Easier way to define enthalpy is the change in temperature

Entropy = change in disorder. Higher disorder = more entropy

Free energy = ability and availability to do work.

So when a gas cools down to a liquid, it's entropy is decreasing because it's becoming less disorder (molecules in the gas phase are much further apart; they move faster, and also collide more often). In the perspective of the system, it's negative entropy.

When a gas condenses, it's also releasing heat to the environment (just think backwards, if liquid water absorbs heat to boil, then the reverse, condensation, releases heat).

Free energy is the system's availability of left over energy (enthalpy minus entropy). This is the energy that is put to do work. In this case the energy released (enthalpy) is higher than the energy "lost" due to decrease in entropy, your overall free energy is negative, which means that there is some left over energy that can be put to work (example: power plants that boils water to turn turbines for electricity). You should know the formula
(delta) G = (delta) H - T*(delta)S

Answer 6

Ask away if you have more questions

Answer 7

What do you not understand about the question?