Question

A system fitted with a piston expands when it absorbs 52.7J of heat from the surroundings. The piston is working against a pressure of 0.693 atm. the final volume is 63.2L. what was the initial volume of the system if the internal energy of the system decreased by 107.4J?

Answer 1

Answer: The initial volume of the system is 60.29 L.

Step-by-step explanation:

According to the first law of thermodynamics,

`\Delta U = Q - W`

As it is given that heat is being added to the system so,
`\Delta H` will be positive. And, work done on the system is negative and work done by the system is positive.

So here,
`\Delta U` = -107.4 J

Q = 52.7 J

P = 0.693 atm

And, W = PdV

or, W =
`P (V_(final) - V_(initial))`

So,
`\Delta U = Q - P (V_(final) - V_(initial))`

-107.4 J = 52.7 J - 0.693 \times 101.325 (63.2 - V)

-160.1 = -43.79 - 70.21 (63.2 - V)

63.2 - V =
`(160.1 + 43.79)/(70.21)`

- V = 2.90 - 63.2

V = 60.29 L

Thus, we can conclude that the initial volume of the system is 60.29 L.