Interactive, scaffolded model
This Activity Requires:
Important! If you cannot launch anything from this database, please follow the step-by-step instructions on the software page.
Please Note: Many models are linked to directly from within the database. When an activity employs our scripting language, Pedagogica, as do some of the "guided" activities, the initial download may take several minutes. Subsequent activities will not take a long time. See this page for further instructions.
In this model-based activity, students will learn the main concepts behind the process of dissolving. They begin by discovering the properties of ionic and polar compounds and observe that in order to be water-soluble, molecules should carry an electrical charge.
Working with models, students compare the solubility between ionic compounds such as table salt, polar organic molecules such as glucose, and non-polar organic molecules such as oil. They observe how water molecules attract ionic or polar substances, leading to the dissolving of various materials, and how non-polar molecules are pushed out by water, "preferring" to stick to each other.
Students will be able to:
1a. What happens to salt on an atomic level (include molecules and ions in your description) when it dissolves in water? Describe the way in which the salt and the water interact.
1b. Alcohol is slightly polar. What happens to salt on an atomic level when it is placed in alcohol?
1c. Draw a picture that shows a salt solution in water. Be sure to label your picture or provide a key for any symbol you use.
1d. Draw a picture that shows a salt solution in alcohol. Be sure to label your picture or provide a key for any symbol you use.
Water is a great solvent, but all substances that water can dissolve must be either polar or ionic (either positively or negatively charged). The polar water molecules attract charged particles and push out non-charged particles. Water is attracted to itself, to other polar molecules, ionic substances, and to non-polar substances.
Additional Related Concepts