What will be the change in internal energy when work done by the system is 210 J and heat absorbed is 20 J?
Correct answer: A. -190
- A. -190
- B. 190
- C. 90
- D. -90
Explanation
In thermodynamics, heat entering the system is taking as positive, and heat leaving the system is taken as negative.Similarly, work done by the system is taken as positive, and work done on the system is taken as negative in Physics. While the opposite is true for Chemistry.Change in internal energy is given byΔU = Q - WΔU = 20 - 210ΔU = -190 J
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About First Law of Thermodynamics
The first law relates heat supplied, work done and the change in internal energy through energy conservation. Problems use sign conventions and apply the law to isothermal, adiabatic, isobaric and isochoric processes. Internal energy is a state function, while heat and work depend on the path followed.
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