- #1
stunner5000pt
- 1,461
- 2
Calculate delta S for the system when the state of 3.00 mol of a monoatmoic perfect gas for which [tex] C_{p,m} = \frac{5}{2} R [/tex] is changed from 298.15K and 1.00 atm to 398.15K and 5.00 atm.
Now [tex] \Delta S = n \ R ln \frac{V_{2}}{V_{1}} + n C_{v} ln \frac{T_{f}}{T_{i}} [/tex]
but when i do that i get an answer that is -36 J/K which is not right the answer given 22.1 J/K.
what am i doing wrong i know that Cp is for constnat pressure but in this case the pressure is not constant! Neither is the volume. (at least it doesn't say otherwise)
Now [tex] \Delta S = n \ R ln \frac{V_{2}}{V_{1}} + n C_{v} ln \frac{T_{f}}{T_{i}} [/tex]
but when i do that i get an answer that is -36 J/K which is not right the answer given 22.1 J/K.
what am i doing wrong i know that Cp is for constnat pressure but in this case the pressure is not constant! Neither is the volume. (at least it doesn't say otherwise)