Question

if salt is dissolved in water, what is the sign of enthalpy of solute, enthalpy of hydration, sign of entropy.

I think it's positive, negative.

The sign of entropy is positive, right? If I am correct, can you explain why it's positive.

Answer 1

I don't know what you mean by enthalpy of the solute. I agree that the enthalpy of hydration is negative and that AND that the sign of entropy is positive. The reason it is positive is that the ions in solution is less ordered than in the crystal. (In the crystal, the ions are locked into their positions but in the solution they are free to move about.)