I've already done #2 can someone help me with #3?

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.

What do you mean by that? like the contents? the thc level?

Thermohaline circulation and gyres