Answer
Assume that an ideal gas expands without a change in
temperature (isothermally) and, in the process, 3.40 x 103 J of
work is performed.
a. What
is the change in internal energy of the gas?
b. How
much heat is absorbed during this expansion
a. We
use the first law of thermodynamics
DU
= Q - W. Since work is done by the gas, the sign of W is positive (be
careful with signs).
DU
= 0 for this process since the temperature did not change.
b. From
above Q =
DU
+ W = 0 + 3.40x103 J = 3.40x103 J