## What is q equal to in the second law of thermodynamics?

$\Delta S = \frac{q_{rev}}{T}$

Kobe_Wright
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Joined: Fri Sep 28, 2018 12:16 am

### What is q equal to in the second law of thermodynamics?

As in how would it be presented in a problem and in what units?

Lauren Huang 1H
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Joined: Fri Sep 28, 2018 12:16 am

### Re: What is q equal to in the second law of thermodynamics?

The second law of thermodynamics states that delta S=q/T=nRln(V2/V1). So q=nRTln(V2/V1) if you multiply both sides by temperature. I believe the unit for q is Joules.

Summer de Vera 2C
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Joined: Fri Sep 28, 2018 12:16 am

### Re: What is q equal to in the second law of thermodynamics?

Lauren Huang 1H wrote:The second law of thermodynamics states that delta S=q/T=nRln(V2/V1). So q=nRTln(V2/V1) if you multiply both sides by temperature. I believe the unit for q is Joules.

Wouldn't you have to divide rather than multiply both sides by T?

BenJohnson1H
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Joined: Fri Sep 28, 2018 12:17 am

### Re: What is q equal to in the second law of thermodynamics?

T can be completely canceled out. Think of it as the -q=w. Because the function for work involves the multiplication of T but deltaS is q/T, the q is simply taken out and the negative sign is omitted.

Kobe_Wright
Posts: 83
Joined: Fri Sep 28, 2018 12:16 am

### Re: What is q equal to in the second law of thermodynamics?

Summer de Vera 2C wrote:
Lauren Huang 1H wrote:The second law of thermodynamics states that delta S=q/T=nRln(V2/V1). So q=nRTln(V2/V1) if you multiply both sides by temperature. I believe the unit for q is Joules.

Wouldn't you have to divide rather than multiply both sides by T?

I believe its divide;.

Kobe_Wright
Posts: 83
Joined: Fri Sep 28, 2018 12:16 am

### Re: What is q equal to in the second law of thermodynamics?

BenJohnson1C wrote:T can be completely canceled out. Think of it as the -q=w. Because the function for work involves the multiplication of T but deltaS is q/T, the q is simply taken out and the negative sign is omitted.

Thanks Ben that helps!!!