Exploring the Science: Does Adding Dish Washing Liquid and Salt to Water Lower Freezing Point?

Have you ever wondered if adding dishwashing liquid and salt to water could lower its freezing point? This question might seem a bit odd, but it’s actually rooted in the science of freezing point depression, a phenomenon that occurs when a solute is added to a solvent. In this case, the water is the solvent and the dishwashing liquid and salt are the solutes. Let’s delve into the science behind this interesting question.

Understanding Freezing Point Depression

Freezing point depression is a colligative property of solutions, which means it depends on the number of solute particles in the solution, not on the type of particles. When a solute is added to a solvent, it disrupts the equilibrium between the liquid and solid phases of the solvent, making it harder for the solvent to freeze. This results in a lower freezing point.

Role of Salt in Lowering Freezing Point

Salt is a well-known substance for lowering the freezing point of water. This is why it’s often used to melt ice on roads and sidewalks during winter. When salt is added to water, it breaks down into its component ions, sodium and chloride. These ions interfere with the water molecules’ ability to form ice crystals, thus lowering the freezing point of the water.

Effect of Dishwashing Liquid on Freezing Point

Dishwashing liquid, on the other hand, does not lower the freezing point of water to the same extent as salt. This is because dishwashing liquid does not dissociate into ions when added to water. However, it can still have a minor effect on the freezing point due to the presence of dissolved particles in the solution.

Combining Salt and Dishwashing Liquid

When both salt and dishwashing liquid are added to water, the freezing point will be lower than that of pure water. However, the effect will be primarily due to the salt, with the dishwashing liquid contributing only a minor additional effect.

Does the Solution Get Colder in the Freezer?

While the freezing point of the solution is lower, this does not mean that the solution will be colder when placed in the freezer. The temperature of the solution will depend on the temperature of the freezer, not on the freezing point of the solution. However, the solution will remain liquid at temperatures where pure water would freeze, due to the lowered freezing point.

In conclusion, adding dishwashing liquid and salt to water does lower its freezing point, primarily due to the presence of salt. However, this does not make the solution colder when placed in a freezer. This is a fascinating demonstration of the principle of freezing point depression, showing how the addition of solutes can affect the physical properties of a solution.