Compressing a System

Moderators: Chem_Mod, Chem_Admin

Uma Ramaratnam 2I
Posts: 21
Joined: Fri Sep 25, 2015 3:00 am

Compressing a System

Postby Uma Ramaratnam 2I » Wed Jan 13, 2016 7:00 pm

If you do work on the system by compressing a piston, I don't understand why the energy would decrease. Wouldn't compressing the piston increase the pressure, which in turn increases the average kinetic energy of the molecules? Doesn't that lead to an increase in temperature which is an increase in energy as well?

Ronald Yang 2F
Posts: 86
Joined: Fri Sep 25, 2015 3:00 am

Re: Compressing a System

Postby Ronald Yang 2F » Wed Jan 13, 2016 7:55 pm

You are right: if you do work on a system by compressing a piston, the energy would increase. w=-PΔV, so when a gas is compressed, ΔV would be negative, so overall, work would be positive. Since ΔU=q+w, assuming the system is under adiabatic conditions, internal energy would increase.

Return to “Thermodynamic Systems (Open, Closed, Isolated)”

Who is online

Users browsing this forum: No registered users and 2 guests