Covalent compound                                            ionic compounds
1)it has low melting and boiling points                it has high melting and boiling points
2)they exist in all 3 states(solid,liquid &              it can only exist in solid state
3)they do not conduct electricity                         they conduct electricity
4)they are soluble in non-polar                            they are not soluble in non-polar       solvents but not soluble in H2O.                      solvents but soluble in H2O.   
-ionic compounds also exist as liquids
-ionic compounds do not conduct electricity, free ions do.
-ionic compounds are soluble in polar covalent solvents. e.g salt is soluble in water
Ionic compounds                         Covalent compounds
bonds are formed by transfer      Bonds are formed by mutual sharing
of electrons.                                   of electrons.
they are hard solids                     they are liquids or gases
they conduct electricity               they do not conduct electricity 
soluble in water.                           soluble in organic solvents.