Queso Posted February 12, 2007 Report Share Posted February 12, 2007 When working with a chemistry experiment, what does the termPolar, and nonpolar mean when regarding to solvents? I've never taken a chemistry class so I have to learn on my own thanks to all of you. Quote Link to comment Share on other sites More sharing options...
ronthepon Posted February 12, 2007 Report Share Posted February 12, 2007 A polar solvent consists of molecules which are electric dipoles, while non polar solvents do not. If you ask me about electric dipoles, well... an electric dipole has a positive charge on one side and a negative charge on the other. Quote Link to comment Share on other sites More sharing options...
eric l Posted February 12, 2007 Report Share Posted February 12, 2007 Tough question if you don't have any background. "Polar" means that you have a unbalance. In water, you have a unbalance because oxygen is much more electronegative than hydrogen. Furthermore, the two bonds between O and H are not exactly opposite, they are at an angle of about 110° rather than 180° (which would make the molecule apolar again). So, because the molecule is not stretched and the oxygen atires the electrons, you have a negative side and a positive side. Typicaly apolar are solvents that do not have such unbalance, either because there is less difference in elctronegativity or because the different parts of the molecule balance each other out. First example : tetra (CCl4) : less difference in electronegativity than between O and H, and a tetraëdric structure. With methane (CH4) you may have more difference in electronegativity, but all parts of the molecule balance each other out. With carbondissulfide (CS2) again the same thing. Second example : benzene (C6H6) - again all parts of the molecule balance each other out. Actually, you have this outbalancing in practically all carbohydrates. Ethanol (alcohol) is less unbalanced than water, but more than ethane. That is why it mixes with both polar and apolar solvents. In general, molecules with an -OH group (ethanol and other alcohols) are polar solvents, because they drop a H+ easily, which leaves them with an O- at one end. I'm affraid this is a bit of a quick and dirty answer, but I can not provide any better at short term. And for once the wikipedia article on solvents is not very helpful either. I hope you'll have more detailed answers from people who are sill active in the field. Quote Link to comment Share on other sites More sharing options...
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