Consider the molecule :C =- O: (Carbon monoxide)....

Question

Is this triple bond polar or non polar ?

Are the electrons in the triple bond pulled closer to the C on to the O? Explain you resonse, referring to the concept of electronegativity.

Answer 1

electronegativity difference is 0.9 which means the bond is polar. Electrons are pulled closer to O because it's more electronegative.

Answer 2

This is one of those where the simple answer doesn't work.   There is indeed a triple bond between C and O in carbon monoxide, so Lewis theory works.  But the electronegativity difference would predict that the molecule is polar, with the negative end of the dipole on oxygen.  Actually, CO is only very slightly polar, and the negative end of the dipole is on the carbon atom.  Lewis theory helps understand why the negative end of the dipole is on carbon, since the best resonance structure for CO has a negative charge on carbon.  See the structure section of the wikipedia article on carbon monoxide.