Answer to Question #108874 in General Chemistry for jagdeel singh

Question

why is OK the alignment of molecules in polar dielectric is perfect? please this is urgent

Answer 1

Molecules of polar dielectrics in terms of electrical properties are dipoles.

A dipole is a system of two identical in magnitude and opposite in sign charges located at some distance from each other.

In the absence of an external electric field of a dipole molecule of a polar dielectric,

making chaotic thermal motion, they are oriented in various directions. The electric fields of these dipoles completely cancel each other out, and the resulting field

equal to zero in all areas of the dielectric.

But if we put such a dielectric in an external field E0, then it will “expand” the dipoles so that

they will be oriented along the lines of tension (the “minuses" of the dipoles will turn

to the left - to those "pluses" that create an external field).

Under the action of an external electric field, polar molecules line up along the direction of the external field.

This is ideal, since a clear alignment of molecules occurs from the chaotic state of molecules