Module 4 Intro

Module 4—Properties of Solutions

Explore

 

Try This

 

Fill a cup with approximately 100 mL of lukewarm water. Add a teaspoon of salt, stirring until all of the salt has dissolved. Repeat this procedure until you notice salt on the bottom that does not dissolve, no matter how much you stir.

 

What you are observing is an example of a saturated salt solution. You were probably able to get 5 teaspoons to dissolve, but the sixth one would not.

 

Now pour the solution into another glass, making sure none of the undissolved salt is transferred. Put this glass in your freezer for about half an hour, and then observe it. Record your observations. Allow the cooled salt water from the freezer to sit at room temperature. Record any changes that occur.

 

Can you explain the changes that occurred with the salt water as you cooled it and allowed it to warm?

 

Send your observations and your explanation for these changes to your teacher. Where possible, use appropriate terms that have been introduced in Lessons 1 and 2.