Experiments on Diffusion of Solids in Liquid

Sugar Into Water

• One of the easiest projects to do to illustrate the dissolution of a solid into a liquid involves. dissolving spoonfuls of sugar in water. Have children explore and describe both the sugar and the water prior to mixing. If desired, have the students taste each item before mixing as well. Then, have the children mix the sugar into the water to watch it dissolve. Ask the children to describe the appearance and taste after the sugar has dissolved, as well as what they observed during the process of dissolution. A fun addition to this project involves having the children dissolve the sugar in a variety of ways. For example, compare the length of time it takes for full dissolution to occur while shaking as opposed to stirring. Or, use different temperature water and compare dissolution of the sugar. For each of these, ask children to make a hypothesis before beginning and then check their hypotheses at the conclusion of the experiment.

Cornstarch Into Water

• Dissolving cornstarch in water is a fun activity that can prove to be messy, but entertaining as well. Children can mix the cornstarch with their hands or with spoons or spatulas. Depending upon the ratio, the solution may be more or less viscous. For older students, you can use different temperature water or explore the use of different ratios of cornstarch or water and make appropriate hypotheses.

Comparing the Ease of Dissolving Solids

• Children can compare the level of difficulty of dissolving various solids. For example, students can hypothesize which will dissolve most or least quickly: lump sugar, flour or bouillon cubes. After the experiment, they can discuss what factors contribute to the ease of dissolution.

Comparison of Ease of Dissolution ̵1; Liquid Changes

• Children can also compare how solids dissolve in liquids using various different liquids. You may choose to use one or more types of solid (such as sugar or flour) and several liquids. Some liquid ideas are water, vinegar, tea and juice. Students can hypothesize in which liquid solids will more quickly dissolve and then discuss afterward the result of their study and what factors may have contribute to a quicker or slower dissolution.