**Problem : **

Reproduce a drawing of a Carnot cycle.

See .

**Problem : **

On your Carnot cycle drawing, shade the region that represents the heat consumed by the system at the higher temperature.

Heat Consumed at
*τ*
_{h}

**Problem : **

On the same drawing, now shade in a distinct manner the region that represents the heat that is unable to be converted to work.

Heat Unusable by the Device

**Problem : **

Suppose we have a heat engine in which
*σ*
_{H} - *σ*
_{L} = *N*
_{0}
, where
*N*
_{0}
is Avogadro's number. Suppose further that
*T*
_{l} = 300*K*
and
*T*
_{h} = 600*K*
. Give the work done per cycle.

The work done is the product of the temperature difference and the
entropy difference, so
*W* = 300*k*
_{B}
*N*
_{0} = 2493
Joules.

**Problem : **

For an isothermal and isobaric process, what is the change in the Gibbs free energy?

We simply use the identity associated with the Gibbs free energy, and
letting
*dτ*
and
*dp*
be zero, we find:
*dG* = *μ* *dN*
.