# Thermodynamics - Whcih isotherm has higher temperature?

#### Amith2006

Sir,
Two isotherms are given. How do we identify which one is at higher temperature? The area of the rectangle formed with P & V as sides seems to equal for both the curves. So I think the temperatures are equal. But the answer given in my book is T1<T2.
I am herewith attaching the P-V diagram.

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#### Chi Meson

Homework Helper
I can't see the attachment yet, but the temperature is greater on an ideal gas PV diagram at the locations where the product of P*V is greater. This means that as go up-and-right on the PV diagram, you will increase in temperature.

#### Andrew Mason

Homework Helper
Amith2006 said:
Sir,
Two isotherms are given. How do we identify which one is at higher temperature? The area of the rectangle formed with P & V as sides seems to equal for both the curves. So I think the temperatures are equal. But the answer given in my book is T1<T2.
I am herewith attaching the P-V diagram.
I can't see your diagram yet but note: the area of the rectangle of sides P and V measures (PV =) nRT. If n differs between the two gases, the PV area might be the same but the temperatures are not.

AM

#### Amith2006

Sir,
I dont have words to thank you. This is a service to all students like me.

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