Why H-CL has polar bond while CL-CL is non polar bond?

Answer 1

Polarity of bonds are determined by the electronegativities of the elements involved in the compound. If one atom in the compound has a greater electronegativity than another atom in the compound, it will attract electrons more strongly. When the difference in electronegativity between two atoms is between about 0.4 and 1.7, then the bond is said to be polar covalent. A difference between 0 and 0.4 is nonpolar.

So take molecular chlorine. Since the two atoms involved are the same and have the same electronegativity, the difference is zero (but doesn't necessarily mean the electrons are always evenly shared). The bond in Cl2 is indeed non-polar. Then take hydrochloric acid. Hydrogen's electronegativity is 2.2 and chlorine's is 3.16. The difference between the two is 0.96, indicating that it's a polar bond.

Answer 2

when hydrogen bonds with chlorine the chlorine atom has lone pairs which causes the bond not to be linear shaped that is why it is polar but as for chlorine and chlorine they both have lone pairs and the shape is linear.what i am trying to say is if a bond is linear shaped it cant be polar.

Answer 3

Whether a molecule is polar or not depends on the electronegativity of its elements. Electronegativity is essentially how much of a pull an atom exerts on the electrons (which are negatively charged) in a bond. In Cl2 there are two identical chlorine atoms with the exact same electronegativity. Since both atoms exert the same pull on the electrons, they do not go more to one end than tot he other and the molecule remains nonpolar. In HCl there is one chlorine atoms and one hydrogen atom. Chlorine is much more electronegative than hydrogen and so the electrons will be pulled toward its end of the molecule more than to the hydrogen. As a result the chlorine gets a partial negative charge and the hydrogen gets a partial positive charge, making it a polar molecule.