Recently I was wondering why deodorant is cold when its comes out of the spray can. Some explanations say that it is because of a change in pressure. But looking at the ideal gas law T = PV/nR and both n and R are constant. And for every decrease in pressure there should be an increase in volume (Boyle's law:PV=constant). Therefore T should be constant. The error in this logic could be that this only applies to ideal gases. If so, what property of the deodorant makes it act like this?