@hansika Hi, sorry, I missed you yesterday but I see you have an answer.

@JohnRennie hi

@AshishAhuja Hi :-)

In this question I realize that the total entropy will increase and the internal energy of the system which initially had a higher temperature will decrease, but I can't figure out which system had a higher temperature initially.

Hmm, good question.

At constant volume dU = dq and dq =T dS so dU/dS = T

ohh got it

So you can tell which has the higher temperature from the gradient dU/dS.

yup the answer given is C. That works.

thanks

:-)

is there any tips for stupid people like me to excel exam for Olympiad level question? I don't think any average people with hard work can do that.

i don't know how everyone can answer so fast with great accuracy but i answer slowly and carefully but I make mistake.

@JohnRennie is my explanation correct?

@BannedUser depends on how young you are, if you are in 12th you probably missed the train

@JohnRennie no problem sir : )

@AdilMohammed the chemical equivalent of potential energy is the Gibbs free energy, and this includes entropy. So in chemical processes changes in entropy affect the potential energy. And when solvent molecules pass from the lower to the higher concentration it increases the overall entropy of the system.

This will cause osmotic flow even if the enthalpy change is zero or even if the process is endothermic.