Jay asked in Science & MathematicsChemistry · 1 decade ago

How to determine whether a compound is polar or nonpolar given only its formula?

Examples:

Are the following polar or nonpolar?

-NH3

-CH3CH2CH3

-HCl

Also...

Example problem:

Determine whether each of the following compounds is soluble in hexane:

water (H2O)

propane (CH3CH2CH3)

ammmonia (NH3)

hydrogen chloride (HCl)

Please give me a simple step by step response so that I may understand. I really need help.

Thanks in advance! :)

1 Answer

Relevance
  • Anonymous
    1 decade ago
    Favorite Answer

    1) Check whether it has electronegative elements ( the group 7 elements) eg. Cl, F,N. The others down group 7 can be ignored. The compounds with these elements are polar.

    2) check the direction to see if the polarity of the elements cancel each other out.eg, O2

    3) Check if they can form hydrgen bonds in water. It must have either a Fluorine, Oxygen or Nitrogen attached to a H atom. And have a free electrons in their shells.

    NH3 is polar (hydrogen bonding)

    Propane is not (the only bonds are vander waals forces)

    HCl is polar.

    Water is polar

    Source(s): My brains
Still have questions? Get your answers by asking now.