The dipole moment of a molecule is a measure of its overall polarity, which arises from the difference in electronegativity between the atoms in the molecule and their arrangement in space. It is represented by the Greek letter mu and is measured in Debye units D .Carbon dioxide CO2 has a linear molecular geometry, with the carbon atom in the center and the two oxygen atoms on either side. The carbon-oxygen bonds are polar due to the difference in electronegativity between carbon 2.55 and oxygen 3.44 . However, because of the linear geometry, the two bond dipoles are equal in magnitude but opposite in direction, effectively canceling each other out. As a result, the net dipole moment of CO2 is zero 0 D .Water H2O , on the other hand, has a bent molecular geometry with a bond angle of approximately 104.5 degrees between the two hydrogen atoms and the oxygen atom. The oxygen-hydrogen bonds are also polar due to the difference in electronegativity between oxygen 3.44 and hydrogen 2.20 . In this case, the bond dipoles do not cancel each other out because of the bent geometry. The net dipole moment of water is approximately 1.85 D, which indicates that water is a polar molecule.In summary, the dipole moment of carbon dioxide is zero due to its linear molecular geometry and the cancellation of bond dipoles, while the dipole moment of water is 1.85 D due to its bent molecular geometry and the presence of a net molecular dipole. This difference in dipole moments results in different physical and chemical properties for these two molecules, such as water's ability to form hydrogen bonds and its higher boiling point compared to carbon dioxide.