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Which liquids are polar and non polar? Why? (1 Viewer)
- Thread starter kasser
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someth1ng
Retired Nov '14
Polar, polar, polar, non-polar, non-polar.
It's to do with the distribution of charge on their molecules that make them.
SuchSmallHands
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Agreed with someth1ng except that your teacher probably wants you to note that ethanol's hydroxyl group is polar but its ethyl group is non polar, thus it can sort of act as both.
Polarity is about the electronegativity differences between constituent atoms. For example, in water, oxygen is much more electronegative than hydrogen. As such, it wants the electrons much more and so pulls them more strongly toward itself than hydrogen is capable of doing. What you're left with is a slight negative charge where the oxygen is, as it has concentrated the electrons closer to itself, and a slight positive charge on the hydrogen as the electrons are being pulled further from it by the oxygen. Thus, the molecule is polar.
Polarity is about the electronegativity differences between constituent atoms. For example, in water, oxygen is much more electronegative than hydrogen. As such, it wants the electrons much more and so pulls them more strongly toward itself than hydrogen is capable of doing. What you're left with is a slight negative charge where the oxygen is, as it has concentrated the electrons closer to itself, and a slight positive charge on the hydrogen as the electrons are being pulled further from it by the oxygen. Thus, the molecule is polar.
someth1ng
Retired Nov '14
You also need to consider geometry. If it's symmetric like CO2 and CF4, even with differences in electronegativity, it is non-polar.