Dipole going from positive to negative
Posted: Sun May 20, 2018 9:09 pm
Can someone please explain why dipole movement goes from positive to negative. Thanks.
Re: Dipole going from positive to negative
Posted: Sun May 20, 2018 9:19 pm
The direction of dipole moment is from positive poles to negative poles because the electrons in covalent bonds are not always equally shared. When there is an increasing difference in electronegativity, it results in an increasing difference in the charge of the two atoms, increasing the ionic character of a covalent bond (Polar Covalent Bonds).
For example, the bond between hydrogen and chlorine is not completely covalent because due to the higher electronegativity of chlorine it attracts electron clouds from hydrogen. Though it doesn't completely make it polar opposite charges, part of the hydrogen atom gets taken away by chlorine - making hydrogen positive and chlorine slightly negative. This movement is thus from positive to negative.