Question

The ammonia molecule (NH3) has a dipole moment of 5.0×10?30C?m. Ammonia molecules in the gas phase are placed in a uniform electric field E? with magnitude 1.8×106 N/C .At what absolute temperature T is the average translational kinetic energy 32kT of a molecule equal to the change in potential energy calculated in part (a)? (Note: Above this temperature, thermal agitation prevents the dipoles from aligning with the electric field.)

Answer 1

Step-by-step explanation:

Formula for change in the potential energy of the ammonia molecule is as follows.

U =
`p * E`

Here, dipole moment is p and electric field is E.

Putting
`5.0 * 10^(-30) C m` for p and
`1.8 * 10^(6) N/C` for E in the above equation is as follows.

U =
`p * E`

=
`5.0 * 10^(-30) C m * 1.8 * 10^(6) N/C`

=
`9.0 * 10^(-24) N m * J/ 1 N m`

=
`9.0 * 10^(-24) J`

Therefore, we can conclude that the change in the potential energy of the ammonia molecule is
`9.0 * 10^(-24) J`.