## Changing the energy of a system

004643111
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### Changing the energy of a system

According to the course reader page 8, the ways of changing the energy of a system include:
Adding or removing the amount of substance in a system, heating/cooling, or putting work on the system. What are the equations to calculate the change of energy for each of these?

Felix Alexie 1A
Posts: 11
Joined: Fri Sep 25, 2015 3:00 am

### Re: Changing the energy of a system

I believe the equation for the change in heat is q=C*n*change in T
the work on the system one can be found on the next page (pg 9)

I'm not 100% sure on the removing the substance one. Hope I helped!

Chem_Mod
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### Re: Changing the energy of a system

This is rather a conceptual question rather than a computational. Thus, my advice is to trying to understand it instead of linking it to a certain equation. As the above discussion pointed out, one is q=mCsp(deltaT). So when you change the amount of a substance, you can change the heat release/absorb. Heating and cooling add/remove energy as heat (think of the way you sweat to cool down your body). Doing work results in losing energy (you burn calories by running around) and work done on the system results in an increase in energy of the system. (w=-$\int PdV$