2
$\begingroup$

Boiling point, as I understand, generally depends on molar mass and the intermolecular interactions in the liquid phase.

  1. What are the other influencing factors?
  2. What intermolecular forces are present in liquid metals?
  3. Why does the boiling point of manganese deviate?
$\endgroup$
4
  • 1
    $\begingroup$ Here are the graphs for the melting point and boiling point of the transition metals, showing how manganese has anomalous behaviour. I've been looking for an explanation myself for a while now. $\endgroup$ Jun 12, 2015 at 12:19
  • $\begingroup$ Well, Mn is clearly different given that the room temperature crystal structure is cbcc_A12, rather than standard bcc for Cr and Fe (although Fe would not be bcc except for the magnetic term in the free energy). For Cr and Fe, the cbcc phase has more than 10kJ/mol excess free energy over the stable bcc at room temperature. Mn than transitions to cub_A13, than fcc_A1, than finally bcc_A2 before melting. Clearly Mn has difficulty figuring out what it wants to do, bonding wise. However, cbcc_A12 Cr would melt around 1000K, and cbcc_A12 Fe not much higher. $\endgroup$
    – Jon Custer
    Jun 12, 2015 at 17:27
  • $\begingroup$ I think the dip in melting point curve for Manganese is because while the others release 2+ electrons into the pool and get the Argon configuration, Manganese releases 2 to get half-filled stability...then as the number of electrons released increases, the melting point increases again...until zinc releases 2 electrons for fully-filled stability. $\endgroup$
    – user76710
    Jun 13, 2015 at 1:58
  • $\begingroup$ For point 3-see this:-chemistry.stackexchange.com/questions/4766/… $\endgroup$ Apr 22, 2016 at 12:42

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.