Intermolecular Forces by Lizelle Swanepoel https://padlet.com/lizellexs/mgptnx84ru7 en-us 2019-04-07 21:03:25 UTC 2026-01-31 04:40:02 UTC hello@padlet.com Why do substances dissolve (become miscible)? lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349696206
  1. When a solute dissolves, it’s particles proceed towards a state of greater DISORDER. 
  2. At the same time the solvent (a pure homogeneous substance) also becomes mixed with particles of a different kind. 
  3. There is an overall increase in disorder (called entropy), which is the driving force in the dissolution process. 
  4. Despite this increase in disorder, which aids dissolution, not all substances dissolve. 
  5. Two substances mix perfectly into solution (i.e. dissolve) iff:
  • INTERMOLECULAR FORCES between the molecules/ions of the substance are OVERCOME. 
  • Therefore, when the forces between the molecules of the solute and solvent are of the same ORDER OF MAGNITUDE, then the molecules of the solvent can take the place of the molecules of the solute. 
  • The result = MIXING. 
  • LIKE DISSOLVES LIKE. 
  • Molecular crystals dissolve in non-polar solvents => solute forms Vd Waals LONDON Forces with solvent.
  • Ionic compounds dissolve in polar solvents => ions of solute form ION-DIPOLE interactions with solvent. 
]]> 2019-04-08 19:49:57 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349696206 Dissociation lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349705818 The breaking up of existing ions.

Dissociation of salts by solvation in a solution = The separation of the anions and cations. 
  • SOLVATION = The process of any solvent surrounding ions of a solute in solution.
  • HYDRATION = The process of water surrounding ions of a solute in solution. 
]]> 2019-04-08 20:21:45 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349705818 Dissolution lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349719086 The process whereby ionic or molecular compounds dissolve = DISSOLUTION. 

Two types of dissolution processes:
  1. Dissociation
  2. Ionization 

Dissociation = Separation of an ionic compound’s cations and anions by the process of solvation. 
E.g.
  • NaCl (s) —> Na+ (aq) + Cl- (aq)

Ionization = The formation of cations and anions from a covalent compound that reacts with H2O. 
E. g.
  • HCl(g)+H2O(l) —> H3O+(aq) +Cl-(aq)
]]> 2019-04-08 21:19:30 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349719086 Dissociation lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349723894 2019-04-08 21:44:48 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349723894 Ionization lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349723958 2019-04-08 21:45:05 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349723958 Ionization lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349725488 The formation of completely new ions. ]]> 2019-04-08 21:53:44 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349725488 lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349727150 2019-04-08 22:03:22 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349727150 Why water and oil don’t mix lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349727865 2019-04-08 22:07:20 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349727865 Properties of water due to hydrogen bonding lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349731828
  • High surface tension
  • High heat capacity
  • Capillary action due to cohesion and adhesion forces
  • Density change due to change in temperature

    • ]]>     2019-04-08 22:36:16 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349731828     Dissolution Exercise lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/349733172 Identify the type of dissolution for each substance below, and write down the equation for the dissolution each compound:

    • HCl

    • KF

    • Mg(OH)2

    • H2SO4

    • NH3

    • AlCl3
    ]]>     2019-04-08 22:46:44 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/349733172     EXERCISE 1 & 2 lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/350282796 2019-04-10 10:31:19 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/350282796 lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/368783717 2019-06-23 07:24:14 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/368783717 lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/368783719 2019-06-23 07:24:14 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/368783719 lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/368783721 2019-06-23 07:24:17 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/368783721 lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/441469400 2020-02-06 11:42:57 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/441469400 MOLECULE SHAPES lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/443495264 Due to VSEPR]]> 2020-02-11 05:43:57 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/443495264 lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/443495278 2020-02-11 05:44:06 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/443495278 SiO2 giant structure lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/454145383 2020-03-04 06:32:05 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/454145383 Diamond vs graphite lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/454145747 2020-03-04 06:33:40 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/454145747 Bonding and IMF Online lesson lizellexs https://padlet.com/lizellexs/mgptnx84ru7/wish/529380356 2020-04-24 21:52:52 UTC https://padlet.com/lizellexs/mgptnx84ru7/wish/529380356