## P1/P2

Volume: $\Delta S = nR\ln \frac{V_{2}}{V_{1}}$
Temperature: $\Delta S = nC\ln \frac{T_{2}}{T_{1}}$

Rita Chen 1B
Posts: 112
Joined: Sat Jul 20, 2019 12:15 am

### P1/P2

Why is it P1/P2 for delta S and V2/V1?

Verity Lai 2K
Posts: 100
Joined: Sat Aug 24, 2019 12:18 am

### Re: P1/P2

Volume and pressure are related inversely, so V=1/P. So when you use the delta S equation, you can replace V with the inverse of P, which results in nRln(P1/P2).

Katie Kyan 2K
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### Re: P1/P2

Using the Ideal Gas Law we know that PV=nRT where P and V have an inverse relationship. This is why we can use P1/P2 in place of V2/V1.

Minh Ngo 4G
Posts: 137
Joined: Thu Jul 25, 2019 12:17 am

### Re: P1/P2

Because P and V has an inverse relationship. If you increases one, one wil decreases (PV=nRT)

Posts: 113
Joined: Thu Jul 11, 2019 12:16 am

### Re: P1/P2

Katie Kyan 2K wrote:Using the Ideal Gas Law we know that PV=nRT where P and V have an inverse relationship. This is why we can use P1/P2 in place of V2/V1.

This is called Boyle's Law.

Anthony Hatashita 4H
Posts: 103
Joined: Wed Sep 18, 2019 12:21 am

### Re: P1/P2

Pressure and volume always have an inverse relationship, so it's P1/P2 instead of vice versa.

Jacob Motawakel
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Joined: Wed Sep 18, 2019 12:20 am
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### Re: P1/P2

Boyle's Law proves that volume and pressure are inversely related.

Nuoya Jiang
Posts: 99
Joined: Sat Sep 14, 2019 12:17 am

### Re: P1/P2

Because in the ideal gas law, P and V are inversely proportionate to each other.

HuyHa_2H
Posts: 100
Joined: Wed Sep 11, 2019 12:15 am

### Re: P1/P2

Pressure and volume are inversely proportional to each other therefore depending on what you're given, the ratio will always be V2/V1 or P1/P2.

Mandeep Garcha 2H
Posts: 100
Joined: Sat Aug 24, 2019 12:17 am

### Re: P1/P2

Pressure and volume are inversely related (when volume increases, pressure decreases, and vice versa). Therefore, it is P1/P2 and V2/V1.

Esha Chawla 2E
Posts: 108
Joined: Thu Jul 25, 2019 12:17 am

### Re: P1/P2

Rita Chen 1B wrote:Why is it P1/P2 for delta S and V2/V1?

According to Boyle's law, pressure and volume are inversely related. As such, if one variable increases, the other variable decreases. Since these two variables are in an inverse relationship, their ratios must also be inverses of each other. Thus, for delta S, it is V2/V1 and P1/P2.