- #1
Joe Cool
- 17
- 3
Hello,
In my textbook I read this example:
A gas in an isolated system expands after pulling out a separating plate, so its volume increases and there is no work or heat exchange.
the entropy of if the ideal gas is
$$\Delta S = n R \ln \frac {V_1} {V_2}$$
and the second law of thermodynamics is
$$\Delta S = \int \frac {\delta Q} T = 0$$
But I didn't understand which of the two formula is the true one?
In my textbook I read this example:
A gas in an isolated system expands after pulling out a separating plate, so its volume increases and there is no work or heat exchange.
the entropy of if the ideal gas is
$$\Delta S = n R \ln \frac {V_1} {V_2}$$
and the second law of thermodynamics is
$$\Delta S = \int \frac {\delta Q} T = 0$$
But I didn't understand which of the two formula is the true one?