Question

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 1

@taramgrant0543664

Answer 2

Canyou walk me through because I wanna understand it and not get the answer

Answer 3

Yes so ummm let's start with enthalpy so this is the thermodynamic potential
H=U+pV is one of the formulas that correspond to enthalpy

Answer 4

what do that formula mean

Answer 5

I was just about to put it lol so this formula is represented by the variables:

H is the enthalpy of the system
U is the internal energy of the system
p is the pressure of the system
V is the volume of the system.

U is the value the is temperature dependent

Answer 6

dU=TdS-pdV

Answer 7

I swear it this look like encrypted codes or something

Answer 8

Maybe I'll try a different way:
Enthalpy describes the change in energy of a system. In the case of water, the "system" is the water itself. At constant pressure, enthalpy refers to changes in heat. An exothermic processes involves a negative change in enthalpy, or a loss of heat. As water vapor condenses into liquid, it loses energy in the form of heat. Therefore, this process is exothermic.

Answer 9

Ok so what's free energy??

Answer 10

We will get to that because we need to talk about entropy first or free energy won't make much sense

Answer 11

Entropy is pretty much the amount of disorder
In solids there is a low amount of disorder because in soilds there is a defined volume and shape
In liquids the disorder increase because there is a define volume but no defined shape
In gases chaos or disorder is high because the is no defined volume or shape the molecules are all over the place

Answer 12

So going from a gas to a liquid you're creating order because you're going from a gas that is is complete disorder to a liquid that has more order

Answer 13

So now there is free energy or Gibbs Free energy as it is also referred to as is the thermodynamic quantity equivalent to the capacity of a system to do work.

Answer 14

It is represented by the equation
dG=dH-TdS

d is those little triangle delta things that normally mean "change in"
G is the free energy
H is enthalpy
T is temperature
S is entropy

Answer 15

We know that dH is negative as heat is given off
We also know dS is negative because it is going from a gas to a liquid

Answer 16

dS is negative
dH is negative

At low temperatures -TdS will be to small to overcome dH
So dG will be negative

At high temperatures -TdS will be big so dG will be positive

Answer 17

When ΔG is negative, a process or chemical reaction proceeds spontaneously in the forward direction.

When ΔG is positive, the process proceeds spontaneously in reverse.

When ΔG is zero, the process is already in equilibrium, with no net change taking place over time.

Answer 18

@taramgrant0543664
Awesome Explanation..

Answer 19

Can you explain free energy changes like you did enthalpy??