- #1

ruiwp13

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## Homework Statement

Calculate the variation of entropy in the following processes:

a) Heating of 18 kg of water from 15 to 40ºC at ambient pressure.

b) Compression of 9 kg of water from ambient pressure to 7atm at the temperature of 15ºC.

## Homework Equations

ΔS=Cp*ln(T_final/T_initial)

## The Attempt at a Solution

So for a) I checked the Cp of water getting 4.18KJ/kgºK and multiplied it by the 18 kg. Then I tried to apply the formula with the Cp and the Tfinal=313.15K and TInitial=288.15K and I think it is correct.

For b) I think I have to use ΔS=R ln (P1 / P2) but I'm not sure. And if it is that expression, the Pressure must be in kPa?

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