Answer/ explanation :
In CO2 molecule, the angle between O-C-O is 180, therefore, when the oxygen atom attracts the electron pair towards itself, then it becomes partially negative and the carbon atom becomes partially positive. The bonds in O=C=O are pointing opposite each other and the bond dipoles cancels each other thereby making it zero.
The dipole in O-H bonds cannot cancel out and that is why water has an overall molecular dipole of 1.85D.
CO2 is a linear molecule, so the dipoles are symmetrical. The dipoles are equal in both magnitude but are differ in point facing opposite directions.
