The crystallization of sodium acetate was exothermic. what would happen to the temperature of solution when you dissolved sodium acetate in water? why would dissociation occur if the solution process is not thermodynamically favorable?

Exothermic means that the reaction produces heat. Dissolving the crystal in water should be endothermic - requiring to heat to produce. The temperature of the water should decrease. The dissociation could still occur if the crystals are hydrophilic and the pH of the solution is appropriate to promote solubility.