Jacobus Henricus van ’t Hoff

Nobel 1901, the very first chemistry prize, “in recognition of the extraordinary services he has rendered by the discovery of the laws of chemical dynamics and osmotic pressure in solutions.” He showed how reaction rates and equilibrium shift with temperature and that dissolved particles generate an osmotic pressure obeying $\Pi V = i \cdot nRT$-style laws like ideal gases. These results founded physical chemistry as a quantitative, thermodynamics-based science.