Two beakers contain clear, colorless liquids. when the contents of the beakers are mixed a white solid is formed. is this an example of a chemical or a physical change?

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.