how do i measure or find polarity.

Question

anonymous · Answer

i know we use the electroneg' but my teacher explainde something different something about opposing bonds canceling out.

anonymous · Answer

I think you are looking for the molecular dipole moment: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/diph2o.html The short answer is that you don't calculate polarity because you can't precisely calculate partial charge. Given partial charge, here is the formula for polarity: $$\mu=Qr$$Where mu is the dipole moment, Q is the partial charge on the atoms, and r is the distance between them. Q is measured in coulombs (C), and r in meters (m). One coulomb meter is a debye (D). Because electrons spend most (all if ionic) of their time around the more electronegative atom, you can tell which atoms will have positive or negative partial charges. Because the charges are vectors, they have a magnitude and a direction, they can cancel one another out. Methane is an example. Look at the chemical structure: http://en.wikipedia.org/wiki/Methane The direction of the bonds in ammonia do not cancel each other out, so it has a net "upward" (if you look at the picture) molecular dipole moment: http://en.wikipedia.org/wiki/Ammonia

anonymous · Answer

$$xa-xb=sqrt{(\Delta)}/23.06$$  xa is known aatom n xb is unknown for the actual way they use it, or you can use the table F=4.0 most important n USUALLY a $$\Delta$$ 1.8 or so its ionic n less than that is covalent