When copper sulphate + carbon = carbon sulphate + copper , does copper turn into a solid or still stays a liquid

Solid, copper becomes insoluble when it is alone.

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.