Question

The direction of dipole moment is $\_\_\_\_\_$.

Answer 1

Hint: We know that the dipole moment depends on the structures of the molecules as well as the electronegativity of the atoms present in the molecule. A dipole moment arises in any system in which there is a separation of charge. They can, therefore arise on ionic bonds as well as in covalent bonds.

Complete answer:
As we know that a dipole moment is a measure of the polarity of a chemical bond between two atoms in a molecule. It involves the concept of electric dipole moment, which is a measure of the separation of negative and positive charge in a system.
Let us take an example of the dipole moment of ${H_2}O$.
$
  {H^{{\delta ^ + }}}\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\mu \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{H^{{\delta ^ + }}} \\
  \,\,\,\,\, \searrow \,\,\,\,\,\,\,\,\,\, \downarrow \,\,\,\,\,\,\,\,\,\,\,\,\,\,\, \swarrow \\
  \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,O \\
  \,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,{\delta ^{2 - }} \\
  $
As from the above structure we can see that the oxygen atom is much more electronegative than the hydrogen atom, the electrons in a water molecule group around it. The existence of a lone pair of electrons in the oxygen atom, causes the water molecule to bend.
Hence the direction of dipole moment is from negative to positive charge.

Note:
 We should note that the symbols ${\delta ^ + }$ and ${\delta ^ - }$ represent two electric charges that arise in a molecule which are equal in magnitude but are of opposite signs. They are separated by a set distance, which is commonly denoted by $d$. In the above example the bond angle in the water molecule is ${104.5^ \circ }$.