The solidification speed of salol is about 2.3 mm/min 21 at 10°C. Using Equation (7.15), estimate the energy barrier q that must be crossed by molecules moving from liquid sites to solid sites. The melting point of salol is 43°C and its latent heat of fusion is 3.2 X 10-20 J/mol. Assume that the molecular diameter is about 1 nm.