## moles and entropy

$w=-P\Delta V$
and
$w=-\int_{V_{1}}^{V_{2}}PdV=-nRTln\frac{V_{2}}{V_{1}}$

Posts: 37
Joined: Fri Sep 28, 2018 12:22 am
Been upvoted: 1 time

### moles and entropy

When you are solving equations for change in entropy, many of the solutions in the manual assume 1 mol when calculating. When can you assume one mol versus useing PV=nRT to calculate?

Posts: 77
Joined: Fri Sep 28, 2018 12:28 am
Been upvoted: 1 time

### Re: moles and entropy

I guess what it comes down to is if you have enough information to calculate moles using pv=nrt, so if you're given all the information then you'd solve for n.

Shubham Rai 2C
Posts: 64
Joined: Fri Sep 28, 2018 12:27 am

### Re: moles and entropy

1 mol should be used in the equations whenever the problem states that the gas is an Ideal Gas and thus has ideal gas properties. When dealing with ideal gas, you assume 1 mole if not explicitly stated.

haleyervin7
Posts: 61
Joined: Fri Sep 28, 2018 12:15 am

### Re: moles and entropy

Does this mean in a problem that gives you the amount of liters of an ideal gas (i.e. 5 L of Ne), you’d assume the molarity is 0.2?