# Entropy of an ideal gas

1) One mole of an ideal gas is changed from 273.15K and 2 atm to 233.15K and 0.4 atm. Calculate delta S for this change in state.

2) Arrange the following chemicals in order of increasing entropy at STP.

n - pentane (g)

methanol ( l)

ethanol (l)

ethanol (g)

https://brainmass.com/chemistry/energetics-and-thermodynamics/entropy-ideal-gas-599217

#### Solution Preview

1. dS = Cpln(T2/T1) - Rln(P2/P1)

We don't know what Cp is, it depends on the type of ideal gas. T2 ...

#### Solution Summary

The entropy equation for an ideal gas is given along with an ordering entropy problem.

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