General properties of covalent compounds
 
1) State of Existence
 
The covalent compounds do not exist as ions but they exist as molecules. There are weak intermolecular forces between the molecules and hence they exists as liquids or gases at room temperature. However, a few compounds also exist in the solid state e.g. urea, sugar, etc. 
 
2) Low melting and boiling points 
 
The melting and boiling points of covalent compounds are generally low. This is because of the fact that the forces between the molecules are weak and can easily overcome at low temperatures.
  
3) Solubility
 
Covalent compounds are generally insoluble or less soluble in water and other polar solvents. However these are soluble in non - polar solvents such as benzene, carbon - tetrachloride, etc.
 
4) Non - conductors
 
Since covalent compouds do not give ions in solution, these are poor conductors of electricity in the fused or dissolved state
 
5) Molecular reactions
 
The reactions between covalent compounds occur between their molecules. These involve the breaking of covalent bonds in reacting molecules and forming new covalent bonds to give molecules of the products. These reactions are quite slow because energy is required to break covalent bonds.
 
6) Directional character of bond
 
Since the covalent bond is localised in between the nuclei of atoms, it is directional in nature.