Polar or Non Polar?
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Is it that because the oxygen got two non ligant pair of electrons and thus its geometry tends to be arched?
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Whether a molecule is polar or non polar doesn't depend on its shape, it depends on electron distribution. Shape and polarity both have the same fundamental cause - electron distribution.
Polar molecules arise when atoms make covalent bonds and the bonding electrons spend more time on average closer to one atom in the bond than another.
If the atoms are identical, such as with H
2 and O
2, they have identical electronegativities and are therefore non-polar.
If the atoms have widely differing electronegativities, the electrons are no longer shared in a covalent bond. One atom grabs another atom's electron(s) completely and ions are formed.
Between these extremes, you get polar molecules. C-H bonds are non-polar because the electron share is equal.
In ethers, the oxygen gets a tiny amount more of the electron distribution than carbon does, but it really is tiny. The result is that ethers dissolve completely in (non-polar) hydrocarbons but won't dissolve in water.