Hydrogen Bonding?

Question

i always thought hydrogen bonding was electrostatic, but 2day my professor said it also has covalent properties. can u explain what this means?

Answer 1

I was taught that the Hydrogen atoms bounce back and forth rapidly between the two host electron clouds at either side of the hydrogen nucleus. This makes a hydrogen bond between say two water molecules more like two 1/2 covalent bonds rather than one whole covalent bond.

Answer 2

The difference between covalent and hydrogen bonding isn't as clear cut as one might think. They both operate by the same force. In a covalent bond bond the two atoms are so close together that the electron shells overlap and the electrons in between the nuclei counteract the repelling electric force with a stronger attracting force.

This can be can be compared to the polar forces in hydrogen bonds in that the electrons on the negative side of one molecule are attracted to the nuclei of a neighboring molecule more than they are repelled by the electrons on the positive side of the other molecule.

In both instances the electrons in between the nuclei act as a sort of electrostatic glue keeping them together. The distinction between the two types of bonds is man made, rather, there is a continuum between hydrogen, covalent, and even ionic bonds.

Answer 3

All bonding is electrostatic in nature, because it entails the interaction between positive and negative charges. Covalent and ionic are just classifications of the degree to which electrons a localized on the bonding atoms. No bond is 100% ionic or covalent. Hydrogen bonds are particularly strong as compared to a conventional dipole-dipole interaction because of the high degree of covalency to. The hydrogen is essentially shared between two atoms in a hydrogen bond, and it can easily jump to one or the other when the bond breaks.

Answer 4

Hydrogen atoms have only a single valence electron.
Oxygen has 2 valence electrons.
4 atoms of diatomic hydrogen will form 2 molecules of hydrogen gas by each molecule sharing their two electrons which orbit both 'H' atoms in a 'Figure of 8' configuration giving 2H2 with single bonds.
Oxygen is also a diatomic molecule and 2 atoms each share their 2 valence electrons in the same way giving rise to the O2 double bond.
If the 4 atoms of 'H' and 2 atoms of 'O' are contained and ignited, EACH of the double bonds of each Oxygen will chemically combine with each of the single bonds of each hydrogen to give 2H2O (2 Molecules of Water).

(H-H) + (H-H) + (O=O) equals 2H2O

Answer 5

Covalence means that an electron is shared between orbitals of two atoms.