What is the order in strength of chemical bonds?

Answer

Hi Kess,

Covalent bonds are known as the very strong bonds. On the other hand, the other bonds are grouped as weak bonds: ionic bonds, hydrogen bonds, dipole-dipole interactions, Van der Waals bonds and nonpolar bonds.

Be careful with the used definitions of bonds and bond strength! This can especially lead to confusion.

The previous line is used in biology/biochemistry: almost always in water. This means that salts split into ions (and therefore ionic bonds are of little value: weak compared to solvation). Ionic bonds therefore only occur (together with the other weak bonds) if they can be formed with many at the same time. This can happen between molecules (intermolecular) or in one and the same large polymer molecule (for example a protein): intramolecular. So also pay attention to your inter- and intramolecular. A large polymer molecule like a protein is formed (covalently: so very solid) as a long thin thread (amino acids together), coils up and is held in shape by masses of weak bonds (all kinds), sometimes also but certainly not always with single covalent disulfide bonds, resulting in an erratic structure. In some proteins, several such structures (called subunits) are bound together, usually via many weak bonds – all types – to form a ‘supramolecular structure’. In water (and therefore biology): molecules formed by covalent – these are the strong – bonds and finished (molded into shape, joined together into larger functional units) by many weak bonds, that’s the rule.

Outside the aqueous environment, eg gas phase, other rules apply (chemistry).

Kind regards,

Myriam Meyers

lecturer industrial biochemistry and microbiology