Solution Basics Take out a sheet of notebook paper. Title it and write your name and class period at the top. Read each slide. On the 4th page you will be directed to open a hyperlink to a simulation on solutions. There are 5 items #1-5 and each has 4 or 5 parts #a, b, c, d, e. Complete these items then review the objectives on the last slide to evaluate your understanding. Turn in your completed paper at the end of class, (or at the start of class tomorrow if you need more time).

Read the Learning Objectives: Know the parts of a solution: Solute and Solvent. Describe what happens when ionic compounds dissolve on a particle-level. Describe unsaturated solutions at the particle-level, and in terms of macroscopic (naked eye) observations.  Explain how changes in solute amount in a given volume affect the concentration of unsaturated solutions. Describe saturated solutions at the particle-level, and in terms of macroscopic (naked eye) observations.  Explain how changes in solute amount in a given volume affect the concentration of saturated solutions. Relate the solubility (maximum concentration at a particular temperature) to the identity of the solute.

Which type of solution could this be? Some Vocabulary: A solution with a concentration of dissolved solute that is less than the solubility is said to be unsaturated. A solution with a concentration of dissolved solute that has reached its “maximum” value is saturated. Solubility is the amount of solute required to form a saturated solution. A solution is said to be supersaturated if more solute is dissolved than in a saturated solution. This is an unstable condition. Which type of solution could this be?

Solution Basics Click on the link above and then click the play triangle to open the PhET simulation. The first compound is table salt, sodium chloride. This is the solute. Water is the solvent. Write a definition for each term. Give the shaker a shake. Sketch and Describe the structure of sodium chloride before it touches the water. Describe what happens as NaCl dissolves. Identify and describe the behavior of the dissolved particles.

Give the shaker some more shakes and watch the value for the number of dissolved particles in the upper right corner. How do the numbers of anions and cations compare? Explain why this relationship exists. Note the number of ‘bound’ particles. What happens to this number as you add more salt? Give the shaker more shakes until the number of cations is around 150. Compare the appearance to after just 1 shake? How could you quantify the concentration of a solution?

Continue to add salt while watching closely. Is there a limit to how much dissolves? If so, what is it for this solution? What happens to additional salt that is added? Note the number of ‘bound’ particles. What happens to this number as you add more salt now? What is happening to the concentration of a solution? Would you say that no salt is dissolving at this point? Use the word ‘equilibrium’ to explain what is happening.

Change to the second tab, Slightly Soluble Salts, and explore several different ionic compounds. Write compound names and sketch the structure of any three examples. Determine the ratio of cations to anions in each compound. Find the particle limit, or solubility, of each compound. What properties of an ionic compound do you think might influence the solubility of the compound?

Look again at the photograph of an ammonium nitrate solution. Is this solution unsaturated or saturated? What macroscopic observations lead you to this conclusion? What would a supersaturated solution look like? On the next slide, review the objectives to evaluate yourself.

Self-Evaluate the Learning Objectives Know the parts of a solution: Solute and Solvent. Describe what happens when ionic compounds dissolve on a particle-level. Describe unsaturated solutions at the particle-level, and in terms of macroscopic (naked eye) observations.  Explain how changes in solute amount in a given volume affect the concentration of unsaturated solutions. Describe saturated solutions at the particle-level, and in terms of macroscopic (naked eye) observations.  Explain how changes in solute amount in a given volume affect the concentration of saturated solutions. Relate the solubility (maximum concentration at a particular temperature) to the identity of the solute.