Work Equation

Moderators: Chem_Mod, Chem_Admin

Caroline C 1G
Posts: 53
Joined: Fri Sep 29, 2017 7:05 am

Work Equation

Postby Caroline C 1G » Thu Jan 18, 2018 8:12 pm

What is the significance of the negative sign in the work equation (w=-PdeltaV)?

Harsha 1J
Posts: 30
Joined: Fri Sep 29, 2017 7:05 am

Re: Work Equation

Postby Harsha 1J » Thu Jan 18, 2018 8:24 pm

If you are putting work into the system (say pressing a piston into a cylinder containing a gas at a given pressure), the volume is becoming smaller, so ΔV is negative. The negative of the pressure times a negative ΔV is a positive value, which matches with the sign convention for putting work in.

Payton Schwesinger 1J
Posts: 45
Joined: Fri Sep 29, 2017 7:04 am

Re: Work Equation

Postby Payton Schwesinger 1J » Fri Jan 19, 2018 2:41 pm

I also think that if the system is doing work on the surroundings, then energy is being released and therefore the work has a negative value... am I thinking about this right?

aaron tang 2K
Posts: 49
Joined: Thu Jul 27, 2017 3:01 am

Re: Work Equation

Postby aaron tang 2K » Fri Jan 19, 2018 11:15 pm

energy is being released which means there's a negative sign

Sara Sasaki 1K
Posts: 48
Joined: Fri Sep 29, 2017 7:05 am

Re: Work Equation

Postby Sara Sasaki 1K » Sat Jan 20, 2018 3:48 pm

Payton Schwesinger 1J wrote:I also think that if the system is doing work on the surroundings, then energy is being released and therefore the work has a negative value... am I thinking about this right?

Yes, that's also right!


Return to “Heat Capacities, Calorimeters & Calorimetry Calculations”

Who is online

Users browsing this forum: Google [Bot] and 2 guests