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How to tell if a molecule is polar or non-polar?

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How to tell if a molecule is polar or non-polar?

Start by drawing its Lewis structure. This rule applies to all molecules except hydrocarbons and molecules with two atoms of the same element.

  • The Lewis structure will help you analyze the shape of the molecule given to you
  • Determine which of the five categories of shapes your molecule falls into linear,tetrahedral,trigonal planar,bent,trigonal pyramid.
  • As learned before,non-polar molecules are perfectly symmetrical while polar molecules are not.
  • Remember that asymmetry applies even if the outer atoms are the same. The arrangement of the atoms matters more.
  • Now,let’s dissect the symmetric molecules. All the atoms that are attached to the central atom must be the same if it is a nonpolar molecule.

    • How can you tell polar from nonpolar?

    If the atoms on the outer edge are all the same, then the molecule is nonpolar. If the atoms on the outer edge are different, even if the shape of the molecule is symmetrical it can still be a polar molecule because the differences in the edge atoms cause the charge to be uneven.

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    Do polar compounds mix with nonpolar compounds?

    Therefore, the tendency for polar molecules to interact with non-polar molecules is minimum. Because the energy released by the formation of dispersion forces between polar and non-polar molecules are not enough to break strong dipole-dipole interactions between polar molecules. Therefore non-polar solutes cannot be dissolved in polar solvents.

    What makes something polar or non-polar?

    The very phenomenon which is responsible for making compounds polar or non-polar is if the electron distribution in the molecule is even or not . As you know, electrons carry negative charge, so if one end of a molecule hogs an excess of the electrons in the molecule, it becomes polar due to its uneven distribution of charge.