1
$\begingroup$

If I am given a phase diagram, how can I determine which phase will have more density?

What should I consider to solve these kinds of questions?

Does the answer have to do with the area that each phase occupies? Or the more area a phase occupies, the more the density?

$\endgroup$
3
$\begingroup$

The solid phase is more dense than the liquid phase. The line that separates solid and liquids bends right.

If the solid phase is less dense than the liquid phase, the line that separates solid and liquids bends left.

$\endgroup$
  • 1
    $\begingroup$ Welcome to chemistry.stackexchange.com. Feel free to take a tour of the site. $\endgroup$ – Jan Feb 12 '16 at 1:28
  • $\begingroup$ This could really do with some explanation of the Clapeyron equation, it is technically an answer, but not much of one $\endgroup$ – orthocresol Feb 12 '16 at 18:59
1
$\begingroup$

Look at the lines on the phase diagram. If you go to a line and then increase pressure you move to a new phase, the denser phase. Edit: Add the below.

enter image description here

Go to the dotted green line. Now, go straight up (increase in P). What happened? You went from solid and liquid being in equilibrium to just liqui. The liquid is more dense than the solid.

$\endgroup$
  • $\begingroup$ could you be more clear ! $\endgroup$ – Maher Aug 13 '14 at 14:46
1
$\begingroup$

The phase which has the higher density is the phase which exists under higher pressure and lower temperature. Thus, in a phase diagram showing pressure as a function of temperature, look for the phase which lies in the upper left region.

$\endgroup$

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.