The pairs of electrons that exist in the valence shells of atoms repel each other as far as possible. This repulsion helps determine the shapes of molecules formed in covalent compounds. This podcast shows some of these possible shapes and explains their formation.

valence shell electron pair repulsion (video) jan 27 07

These chemistry video podcasts are high school chemistry snippets, from Mt Lawley Senior High School.  Check out my YouTube channel https://www.youtube.com/channel/UCDK3TYmYcgTfjrkQ_t_2tCQ 
To help make these resources more useful your feedback would be appreciated.
You may also want to check out my physics video podcasts at www.meaghersphysics.podomatic.com.

Thanks, 
Richard.

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We look at graphs of concentration vs time and rate vs time for the Haber process. Consideration of the value of the equilibrium constant as changes are made to the system at equilibrium are included.

Equilibrium Graphs

In this episode we consider some values of an equilibrium, and show that even if the raw ratio of reactants to products is reversed when a chemical equilibrium is reestablished the value of the equilibrium constant remains unchanged, so long as the temperature remains constant.

Equilibrium Constant Values

This chemistry video podcast looks at the concept of equilibrium as it applies to chemical systems. (It is an old,ie 2006, episode that I inadvertently deleted when trying to get rid of spam comments!) I really must publish more up to date episodes!! I do intend to get more episodes out this year, along with an epub book on intro chem.
Richard

Equilibrium

This chemistry video podcast looks at electrostatic forces and how they are responsible for holding solids together. All four fundamental forces (ie strong, weak, gravitational and electrostatic) are considered. "Mindocular' is a fictional character who has a 'minds eye' with excellent magnification and resolution and can 'see' individual particles in matter, and determine their behaviour. He looks at metallic, ionic and covalent solids.

Mindocular and the opposing forces (video) jan 15th 2009

This chemistry video podcast investigates the reactions of ethanol, 1-butanol (ie butan-1-ol), 2-butanol (ie butan-2-ol) and methyl-2-propanol (ie methylpropan-2-ol) with potassium dichromate, potassium permanganate and sodium metal. We see that tertiary alcohols are less reactive than secondary alcohols, which are less reactive than primary alcohols.

valence shell electron pair repulsion (video) jan 27 07

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