1. why polar covalent compound like ammonia, hydrogen chloride are non-electrolyte in the gaseous state?
Answers
There are certain compounds in which bonds are formed when two atoms share a pair of electrons between them. Each of these atoms contributes one electron and both the electrons (in pair) jointly orbit the nuclei. This produces a bond between the two atoms, known as the covalent bond.
In covalent bonds, electrons are not transferred from one atom to another, but a pair of electrons is shared by two atoms.
A variant of the covalent bond is the co-ordinate bond, where the shared electrons are supplied by the same atom.
In this lesson, you will learn about covalent bonds, the difference between covalent and ionic bonds and co-ordinate bonds.
Covalent bond
Covalent bonds are formed between two or more atoms when they share electrons. They are normally formed between atoms of similar electronegativity and may occur between atoms of same or of different kind.
Example: Hydrogen, oxygen, nitrogen share 1, 2 and 3 electrons respectively, with similar atoms to form molecules. Carbon and hydrogen share electrons to form hydrocarbons.
Covalent bonds can be polar or non-polar. The more the difference in electronegativity, the more is the polar nature of the molecule.
Polar covalent bonds are formed between atoms with difference in electronegativity, for example, water and hydrogen chloride.
Covalent bonds are of three types: single covalent bonds, double covalent bonds and triple covalent bonds.