P1/P2

[Rita Chen 1B]

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

[Verity Lai 2K]

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]

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]

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

[Robin Cadd 1D]

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]

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

[Jacob Motawakel]

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

[Nuoya Jiang]

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

[HuyHa_2H]

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]

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]

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.