Science Experiments with Salt

In the last two experiments with ice I asked you to use salt to melt the ice faster to help with the artistic process. Salt lowers the freezing point of water so the ice at room temperature begins to melt faster. Here’s a simple experiment to help prove that this actually happens.

Take two identical cups of Styrofoam and add half cup water to them. Now in one of them also add a big spoon of salt. Stir it in and place both cups in the freezer for 15 minutes. When you take them out at the end of that time period it will be easy to see that the cup with plain water is ready to form ice and is crystallizing well while the other one with salt is still liquid.

The salt has lowered the freezing point and it will be a while more before the salt water is ready to freeze. Another fun experiment is to make things float using salt in the water. This is sort of like the reason why no one can sink in the Dead Sea. Use an object that floats easily like a plastic spoon and one which usually sinks like an egg.

Now while the plastic spoon will float in plain water, the egg will need close to 100gm of salt being added to the water before it begins to float. Calculate how much salt is needed to make other things like a coin, or an eraser float in a science project.