[samiam]

Compare the work done by 2 mol of ideal gas that expands isothermally
(T=300K) and reversibly from V1 to V2 (V2=2V1) with the work done when the
same gas expands isothermally (T=300K) into an evacuated space.

I think these questions were marked wrong my test, can some one confirm before I go talk to the TA.
Questions:

18.   And thus:

(a)        Change in entropy will be zero

(b)       Change in entropy can be related to 1st Law

(c)        Change in entropy equals *n*RTln(V2 / V1)
- Hide quoted text -

(d)       None of the above ** answer posted online said it was c

on the test I said



18) enthropy= nRln(v2/v1) not nRTln(v2/v2) .the T is
multiplied by change in enthropy to calculated work but not included in calculating enthropy.
I put an answer of none of the above
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16.  Reaction is isothermal, therefore:

(a)             Reaction is isothermal, thus thermal energy equals T x 2V1

(b)             Reaction is isothermal, thus work may be equal or less than
T∆S − ∆E

(c)              Reaction must be a combustion reaction

 (d)    None of the above..onlien it said the answer was b

I said an isothermal ideal gas reaction -w=TΔs- ΔE,  but change in e=0
so i put an answer of none of the above. because there was no option for
-w=tΔs.