4. Arnold put some sand in his aquarium. At first, the water looked muddy. Lat water looked clear. How did this happen?
A Sand dissolved in water.
C. Sand settled at the bottom
B. Sand is white and clear.
D. Sand spread evenly throughou

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.