Question

DO molecules move? for example does ethane flip around when placed in a solution ?

Answer 1

Heat is the measure of the kinetic energy of atoms.

So to answer your question yes, the only time a molecule would not be moving would be at 0 Degrees Kalvin (273 Kalvin is 0 Degrees Celsius).

Temperature is just the speed of particle movement, that is why things turn to gas when hot and become solid when cold.