1
$\begingroup$

The expression given on Wikipedia is (https://www.google.co.in/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwj-_pDA2IfSAhUFto8KHa2kBAwQygQIIDAA&url=https%3A%2F%2Fen.wikipedia.org%2Fwiki%2FEntropy_of_mixing%23Mixing_of_ideal_materials_at_constant_temperature_and_pressure&usg=AFQjCNFVf8mAoquhiL05HeVXC1H3cw54xA) But If I evaluate it as following I get a different answer . $$\Delta S=\int q_{rev}/T=\int pdV/T $$ as p and T are constants $$p(V_1+V_2)/T $$ What is wrong with my method ?

$\endgroup$
1
$\begingroup$

The reference you gave involves mixing two different chemical species together at constant temperature and pressure. The problem you seem to be solving is mixing the same chemical species with itself at constant temperature and pressure. For that process, the change in entropy is zero. If you really intended to determine the entropy of mixing two different chemical species, then the path you identified is not a reversible path for transitioning between the initial and final states of the system.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.