Why is salt added to the ice surrounding the ice cream ingredients? Salt(NaCl) is used in the ice surrounding the ingredients to make ice cream because it lowers the freezing point of ice. The main reason for this is because of the freezing point deposition, Since your adding salt to the ice, it will make it harder for the water molecules to come together and freeze because the salt particles are in the way. Colligative properties will have an effect on the freezing point and the temperautres that that substance will hear or melt. Dissociation can have an affect on the colligative properties. Dissoication has an affect on the ice becoming colder as well. Dissociation will cause for the salt particle to break up into two ions (Cl and Na), so instead of having one particles the two particles will cause for the ice to be colder. All ionic compounds including salt go through dissociation, so they will split into two ions once mixed with water. With salt added to ice an endothermic reaction of the ice will need more energy and a higher temperature,since the freezing point is so low and more energy will be required in order to change its state into a liquid.