[amir.mi]

Hi!
I have 2 questions:
1- if we have a 1 phase solution and then we heat a section of that, so the density of this section decreases. now, has our solution 2 phases ?
2- if we have a salty water and a saltier water, are they 2 phases?
thank you very much and I'm sorry about the broken English i wrote 

[mjc123]

No. They are both 1-phase systems not at equilibrium.