Question

Which of the following compounds is/are polar covalent? H2O, CaCl2, N2, CH4, HNO3

Answer 1

A) Water, H2O is a polar covalent molecule, this is because the oxygen has lone pairs of electrons which makes that the molecule takes a non linear shape.

It has a V shape that makes the oxygen to a partial negative charge this is why this molecule is polar covalent

B) CaCl₂

This molecule is formed by a metal atom with a non metal atom, this gives a ionic bond. It cannot be considered a covalent bond.

C) N₂

Molecules formed by the same atoms are non polar, this is because each atom neutralize the electronegativity of the other.

D) CH₄

This is a simmetric molecule which makes that the molecule doesn´t have an atom with positive charge neither an atom with negative charge.

Methane is a non polar covalent molecule.

E) HNO₃ is not a simmetrycal molecule, therefore is a polar molecule. The H has a positive charge in the molecule, the result is the polarity of the molecule