EK Gen Chem Q29: Ideal Gas Law

[unhappytnt]

So, I am a little confused by this question in EK:

A force is applied to a container of gas reducing its volume by half. The temperature of the gas:

A. decrease
B. increases
C. remains constant
D. it depends upon the amount of force used

I said it remains constant, thinking that as the volume decreases, pressure would increase and thus no change in temperature would occur. However, the answer is B. Can anyone explain how it's possible for both pressure and temperature to increase at the same time?

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[MT Headed]

This is related to kinetic molecular theory, EK Chem page 24.

Basically you did work on the gas. That increases its internal energy, and since this is an ideal gas all that internal energy is kinetic energy. What becomes of this increased kinetic energy? Well, pressure is kinetic energy per unit volume (don't believe me? check out the units!), so pressure goes up. Temperature is (defined) as proportional to average kinetic energy, so it goes up too.

I'd try rereading page 24 again, and if you still don't get it seek alternate sources like TBR or your chem/physics textbooks. EK is notoriously dense and best serves those who already kinda knew the material.

 

[ruchir]

Edit: Ignore

 

[unhappytnt]

This is related to kinetic molecular theory, EK Chem page 24.

Basically you did work on the gas. That increases its internal energy, and since this is an ideal gas all that internal energy is kinetic energy. What becomes of this increased kinetic energy? Well, pressure is kinetic energy per unit volume (don't believe me? check out the units!), so pressure goes up. Temperature is (defined) as average kinetic energy, so it goes up too.

I'd try rereading page 24 again, and if you still don't get it seek alternate sources like TBR or your chem/physics textbooks. EK is notoriously dense and best serves those who already kinda knew the material.

Thanks! That makes sense.