Question

For the type of interactions: (1) Covalent bond, (2) Van Der Waals force and (3) Hydrogen bonding. which represents the correct order of increasing stability?
a.) (1) < (3) < (2)
b.) (2) < (3) < (1)
c.) (3) < (2) < (1)
d.) (2) < (1) < (3)

Answer 1

The order of stability is decided by the strength of the given forces. Thus, we can say that the order of stability is determined by the order of the bond energies of the following forces. Bond energy is inversely proportional to bond order. The wider the space between the groups of the atoms forming the bond in the periodic table, greater is their bond energy.

Complete step by step answer:
-A chemical bond is an interaction between the ions, atoms and molecules. It can be strong bond(like ionic bond, covalent bond, metallic bond) or weak bond(like dipole-dipole interactions, vander-waal forces, hydrogen bond)

-Covalent bond is an intramolecular bond in which atoms share the valence electrons equally or unequally. It is the strongest bond and is generally created in atoms with similar electronegativities.

-Hydrogen bond is a bond formed between hydrogen and atoms with higher electronegativities which make the other atoms attract the shared electron cloud of hydrogen atom thus creating a partial positive charge on hydrogen atom and partial negative charge on the other atoms.

-The atoms that can show hydrogen bonding are fluorine, oxygen and nitrogen as they have high values of electronegativity and are of the appropriate size so as to form a bond with hydrogen.

-van der waal forces are interactions between atoms or molecules based on attraction and repulsion. They are caused by the differences in the polarization between the atoms and molecules and depend on distance between the particles and hence are very weak as they do not include the electron sharing or electron removal.
-Thus, the covalent bond is the strongest as it is created by complete sharing of electrons.

-Hydrogen bond is weaker than covalent bond as it involves partial sharing of electrons which move more towards the more electronegative atom

-vander waal force does not involve any sharing of electrons and decreases with the increase in the distance between the atoms or molecules and hence is the weakest.
Therefore, the correct order of the stability of the bonds is (2) < (3) < (1).
So, the correct answer is “Option B”.

Note: There is a difference between covalent bond and hydrogen bond. Covalent bond is intramolecular bonds and this makes it stronger while hydrogen bond is intermolecular bond. Electrons are shared in covalent bonds while in hydrogen bonds, electrons are pulled towards the more electronegative atom due to higher electronegativity.