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dipole moments and polarization

Posted: Sun May 27, 2018 10:15 pm
by Alysia Garcia 1B
Would a molecule be polar if the dipole moments don’t cancel each other out? like why is water polar if there’s both a negative charge (on the oxygen) and positive charge (on the hydrogen atoms)?

Re: dipole moments and polarization

Posted: Sun May 27, 2018 10:19 pm
by Tarek Abushamma
In water the dipole moments are not linearly opposing each other, which is why they do not cancel each other out. For this reason the molecule is polar.

Re: dipole moments and polarization

Posted: Sun May 27, 2018 10:24 pm
by Chris Fults 1C
Do you mean it is polar because the oxygen is pulling electrons giving it a slight negative charge and the two hydrogens have a slight positive charge? Why doesn't this apply to CH4 which is to my knowledge non-polar?

Re: dipole moments and polarization

Posted: Sun May 27, 2018 10:55 pm
by AshleyLamba1H
Water has the VSEPR type AX4, which is tetrahedral. However, two of these ends are lone pairs, which leaves the two hydrogens connected to oxygen in a bent shape. This is why water is a polar molecule. CH4 on the other hand is non polar; although its shape is also tetrahedral, the central atom has no lone pairs. The symmetry of the tetrahedron allows the four dipoles to cancel.