A cylinder containing an ideal gas is heated at constant pressure from 300K to 350K by immersion in a bath of hot water. Is this process reversible or irreversible?

1
A cylinder containing an ideal gas is heated at
constant pressure from 300K to 350K by immersion
in a bath of hot water. Is this process
reversible or irreversible?
A reversible B irreversible
2
What is the work done by the gas in the
reversible isothermal expansion shown?
A p0V0ln(2) B p0V0 C 2 p0V0 D 0 E none
of these
What is the heat added, Q?
3
No change in internal energy, so WQ
p0V0ln(2).What is the entropy change of the gas?
A p0V0ln(2) B nRln(2) C nRln(1/2) D 0 E
cannot determine
?S Q/T for an isothermal process. Use
p0V0nRT along with Q p0V0ln(2) to find ?S
nRln(2).
What is the entropy change in the hot reservoir
which isadding heat to the gas?
4
In a reversible process, ?S 0. So the entropy
change in the hot reservoir (which is at the same
temperature T as the gas) is -nRln(2). Answer C.
What is the entropy change in the hot reservoir
which isadding heat to the gas?
A p0V0ln(2) B nRln(2) C nRln(1/2) D 0 E
cannot determine
5
We showed, for a Carnot cycle, that QH/TH
Qc/TC -Qc/TcWhat is the change in entropy of
the gas around the entire Carnot cycle?
A p0V0ln(2) B nRln(2) C nRln(1/2) D 0 E
cannot determine
6
Any reversible process consists of adjoining
Carnot cycles. ?S for adjoining segments cancels.
So Entropy, like Internal Energy, is a state
variable, and depends only on the state of a
system (p, V for a gas). -gt You can calculate
entropy changes for irreversible processes by
taking a reversible path to the same endpoint.
Example free expansion to double the volume.
Tf Ti.
7
Entropy changes in non-isothermal processes
Example 1 heating water Example 2a/b heating a
gas at constant V/p