(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A 740g quantity of an ideal gas undergoes a reversible isothermal compression at a temperature of 330 K. The compression reduces the volume of the gas from 0.40 m^{3}initially, to 0.32 m^{3}finally. The entropy change of the gas is equal to:

A) -43 J/K B) -150 J/K C) 43 J/K D) 150 J/K E) 0 J/K

2. Relevant equations

ΔS = nR*ln(Vf/Vi)

3. The attempt at a solution

I actually know exactly how to solve this problem. The only thing is, I haven't been able to determine n, the number of moles, without being given the molar mass.

Is there some method to determine n that I'm missing, or has my prof omitted a vital piece of information (the molar mass)?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Isothermal Compression and Entropy Change

**Physics Forums | Science Articles, Homework Help, Discussion**