Why does NaCl not dissolve in all liquids?

Question

NaCl dissolves in water, but not all other liquids. I'm trying to explain this to a grade 4 student. Can anyone help?

Thank you.

Answer 1

Sodium chloride is an ionic salt. It is made up of sodium ions and chloride ions. Sodium has a +1 charge, chloride has a -1 charge.

Just like magnets attract (N pole to S pole), ionic materials need other ions to pull them out of the crystal and into solution. So you need a solvent that has an ionic character, such as water. Liquids like vegetable oil, or alcohol, do not have that ionic character, and so do not attract the ions to pull them out of the crystal.

If you have a magnet, you can do the following experiment to help with the concept. Put a small pile of paper clips on the kitchen counter, and a small pile of Cheerios there. As him/her to predict which ones the magnet will pick up.

The magnet will pick up the paper clips, but not the Cheerios. Explain to him/her that the paper clips are like water, and are attracted to the magnet (which can represent the ions in salt). The Cheerios are like oil or alcohol, and show no attraction.

Hope that helps!