Work on Surrounding

[Jeilyn Rhee 1J]

What does it mean for systems to do work on the surrounding?

[Cylin Wang 2H]

I am also a little confused about this but I think right now the professor has been referring mostly to:
1. An exchange of matter with the surroundings.
eg: Producing gas and releasing it to the environment.
2. Dislocating/moving part of the surrounding.
eg: Pushing surrounding air out of the way (smoke billowing up from a fire).

Please correct me if my understanding is incorrect/incomplete.

Thank you.

[Audrey Wong 2G]

Hello!

In the case of a system with gas molecules inside of a piston, a system can do expansion work on its surroundings if the volume of the gas increases, causing the volume of the gas to increase, therefore pushing the piston upwards. This would cause negative work to be done, as the energy in the form of work is transferred to the surroundings from the system.

[Keanu Ngo 3B]

Would the freezing of water in an open container cause work down on its surroundings since the density of water in lower than ice?

[Anjana Shriram 2A]

Would the freezing of water in an open container cause work down on its surroundings since the density of water in lower than ice?

Hi! I'm not sure if the example you've given qualifies as work but in lecture, I think Dr. Lavelle said the only form of work we will be dealing with in 14B is work related to a volume change (expansion or compression of a gas).

[Sophia_Francis_1G]

Is essentially means that the system is losing energy through work to what is around the system. For example, if we had a piston and a reaction occurred inside the piston that released heat, the piston would be pushed upwards agains the atmosphere and the system itself would lose energy in the form of work to the surroundings.