The Nobel Prize in Chemistry 1901 was awarded to Jacobus H. van 't Hoff "in recognition of the extraordinary services he has rendered by the discovery of the laws of chemical dynamics and osmotic pressure in solutions".
 

As a result of his investigations in the fields of atomic and molecular theory van 't Hoff has made the most important discoveries in theoretical chemistry since Dalton's time. With regard to atomic theory van 't Hoff, following an idea put forward by Pasteur, advanced the hypothesis that the elementary atoms have attachment points geometrically oriented in space - a hypothesis which in so far as carbon compounds are concerned led to the theory of the asymmetry of carbon atoms and to the founding of stereochemistry. He proved that gas pressure and osmotic pressure are identical, and thereby that the molecules themselves in the gaseous phase and in solutions are also identical. He also discovered how to express the state of chemical equilibrium in reactions and the electromotive force which a reaction can produce; he explained how the transition occurs between the various modifications of the elements, between hydrates of differing water contents, how double salts are formed, etc.