STEMing for Kids: Dissolving candy hearts

Right when children are finally coming down from their sugar-induced holiday comas and exhausting their stashes of sweets, Valentine’s day comes and restocks their sugar supplies. If you are wanting to stir up some heart-shaped chemistry while reducing your child’s Valentine candy hoard with both their approval and participation, dissolving candy hearts is the perfect (and educational) activity!

For this activity, you will need the following supplies:

• Conversation Hearts (the candy)

• Test tubes and test tube holder/rack (you can also use clear glasses/jars)

• An assortment of liquids (such as oil, water, milk, juice, soda, vinegar, rubbing alcohol, etc.)

• Stirrers/spoons (these are optional, as you can let the hearts dissolve without intervention)

• A timer

Fill each test tube/jar/cup with an equal amount of a different liquid (which can offer a great opportunity to practice measurement skills). Add a label that states which liquid is in each container. If your child is an appropriate age, encourage such child to make predictions about which liquids will make the conversation heart candy dissolve quickest and which liquids will be the slowest to dissolve the conversation heart candy.

Once all containers are filled equally, drop a conversation heart candy into each liquid and start the timer. If your child is getting too impatient, they can stir the liquid to see if agitation assists in speeding up the dissolution process of the candy heart.

While waiting for the candy hearts to dissolve, it is the perfect time to talk about solubility. According to Little Bins Little Hands,

Solubility is how well something is able to dissolve in a solvent. What you are trying to dissolve may be a solid, liquid, or a gas and the solvent could also be a solid, liquid, or a gas… [T]he candy will not really dissolve in cooking oil. Why? Because oil molecules are much different than water molecules. They do not attract the sugary solid like water does… Water is the universal solvent…[H]ydrogen peroxide is a denser liquid than the water, so the heart is likely to float quicker as some of it dissolves (see https://littlebinsforlittlehands.com/dissolving-candy-hearts-science/).

Your child will have hours of fun dissolving their Valentine’s candy rather than eating it, and, if you are lucky, you may be able to sneak a chocolate treat or two.