Predict the sign of ΔSsys (is it positive or negative) for each case: molten gold solidifies 3 Ca(NO3)2 (aq) 2 (NH4)3PO4 (aq) --> Ca3(PO4)2 (s) 6 NH4NO3 (aq) 2 NH3 (g) ⇌ N2 (g) 3 H2 (g) NaCl (s) dissolving in water.