Covalent and noncovalent bonds

Question

how can you figure out the type of molecular bonding (covalent) and IMF in pure solutions and in water (noncovalent) if the electronegativities are given?

Answer 1

electronegativity values are used to test whether a bond and the whole molecule is polar or not. e.g. H2 is non polar (same electronegativity of the two molecule which results to zero dipole moment). CH4 is non polar (has polar bondds but the geometry of the whole molecule cancels each dipole moment so the resultant dipole moment is zero) HCl has a polar bond because there is a big difference in the electronegativity of each atom.

after knowing the polarity of a molecule, you will know what imfs govern them. for non polar molecules, london dispersion, for polar molecules, dipole moment, for polar molecules with H and any of C, O, N, hydrogen bonding so on..

Answer 2

Electronegativities can give an indication of the type of bond you are looking at.

If the difference in electronegativities between the tow atoms bound together is:

0 or close to 0 --> you are looking at a non-polar covalent bond

between 0 and 2  --> you are looking at a polar covalent bond

Greater than 2  --> you are looking at an ionic bond

Note that this is just a general rule of thumb, not an exact explanation.