Question

in covalent bonds which of these bonds are polar? N-H, C=O, C-N, O-P

Answer 1

I think it should be C=O

Answer 2

You can look at this
https://www.chem.wisc.edu/deptfiles/genchem/sstutorial/Text7/Tx71/tx71.html


Polar means that there's an electronegativity difference between the atoms large enough such that theres a net dipole moment. This dipole moment means that, theres a net negative charged end on our molecule.

we would also have to consider whether there's a large difference in electronegativity between the two atoms we're interested in.

remember in covalent bonds you can have polar and non polar covalent too. and that has to do with electronegativity difference.

If a compound has an electronegativity difference between the two atoms is less than 0.4- 1 it's most likely going to be non polar covalent and if it's greater than 1.7 it's ionic. also you need to take into account dipole-moments too. if you're dipoles cancel out in your molecule then overall your molecule is non polar.

but let's look at C, and Nitrogen. I believe that for these two that, their difference in electronegativity is probably going to be less than 1 so i'm going to say that's out. also because they are relatively close to each other on the periodic table their difference should be minimal

Electronegativity values; you can actually put these in on a google search.
2.55 Carbon
3.04 Nitrogen
0.49 difference

Oxygen 3.44
Phosphorus 2.19
difference 1.25

Nitrogen 3.04
Hydrogen 2.2
difference 0.84

I would say that they are all polar covalent because there's a large enough difference between them.

Answer 3

Electronegativity difference has to be large for polar covalent bond.
and I support @Photon336 answer.....

Answer 4

@arindameducationusc I think the question was a little ambiguous, I guess virtually all of them can be polar if you look up the values and then subtract them.

Answer 5

yes.... even I feel the same way....I think the question should be which one is more polar.... :D

Answer 6

same, I agree with you