Chemistry
Give reasons for the following:
Molecules of hydrogen and chlorine have single covalent bonds between their atoms while oxygen has a double covalent and nitrogen a triple covalent bond respectively.
Answer
Depending on the number of electron pairs shared, covalent bond is single [-], double [=], or triple [≡] covalent.
Hydrogen — Each of the 'H' atoms contribute one electron so as to have one shared pair of electrons between them. Both atoms attain stable duplet structure resulting in the formation of a single covalent bond [H-H] between them.
Chlorine — Each of the two Cl atoms contributes one electron so as to have one shared pair of electrons between them. Both atoms attain stable octet structure, resulting in the formation of a single covalent bond [Cl–Cl] between them.
Oxygen — Each of the two O atoms contributes two electron so as to have two shared pair of electrons between them. Both atoms attain stable octet structure, resulting in the formation of a double covalent bond [O=O] between them.
Nitrogen — Each of the two N atoms contributes three electron so as to have three shared pair of electrons between them. Both atoms attain stable octet structure, resulting in the formation of a triple covalent bond [N≡N] between them.
Related Questions
Give reasons for the following:
A molecule of methane has four single covalent bonds.
Explain with the help of electron dot diagrams the formation of the following molecules, stating the valency of each element involved.
(a) Hydrogen
(b) Chlorine
(c) Oxygen
(d) Nitrogen
(e) Water
(f) Methane
(g) Carbon tetrachloride
(h) Ammonia
(i) Carbon dioxide
[at. nos. H = 1, C = 6, N = 7, O = 8, Cl = 17]
Give two differences between the covalent compounds – methane (non-polar) and HCl (polar)
Give reasons for the following:
Formation of ammonia involves one atom of nitrogen sharing three electron pairs one with each of the three atoms of hydrogen.