This is a series of experiments, PhET Interactive Simulation activities, and clicker questions to relate macroscopic and molecular representations of homogenenous solutions. Graphing skills are also used.
PhET Activity 1 Learning Goals: Students will be able to:
Identify if a compound is a salt or sugar by macroscopic observations or microscopic
Explain how using combinations of solutes changes solution characteristics or not.
Use observations to explain ways concentration of a solute can change.
Describe ways the formula, macroscopic observations, or microscopic representations of a
compound indicates if the bonding is ionic or covalent.
Lab 1: Determine the solubility of table salt and table sugar in room temperature water using
varying amounts of water.
PhET Activity 2: Learning Goals: Students will be able to
Determine the solubility for some solutes and explain why the solubility cannot be determined for
others given experimental constraints.
Identify the relationships for measurable variables by designing quantitative experiments,
collecting data, graphing, and using appropriate trend lines.
Determine the amount of grams of solute to make a given volume of specified molarity.
After dilution, determine the molarity of a solution.
This is a combination of activities that will take several class periods or a few class periods and homework if students have computer access outside of classtime.
Access to PhET Inteactive Simulations -
Activity 1 Sugar and Salts http://phet.colorado.edu/en/simulation/sugar-and-salt-solutions
Activity 2 Molarity http://phet.colorado.edu/en/simulation/molarity
Lab 1: Sugar, Salt, water, Graduated cylinders, Excel or graphing program or graph paper
Lab 2: I chose the nickel salt because I had a large supply and it has a nice color. I did not
worry that it might not totally dissolve, but just wanted to make sure it was colored and that
dilution would look very different. You could use any number of chemicals and perhaps one that
is more soluble. My jar was full and had not been used in 15 years, so it seemed a good use.
This series of exercises is meant to introduce solutions to students with little background. For more advanced students, parts could be skipped.
See the attached pdf.
See the Teacher pdf or http://phet.colorado.edu/en/contributions/view/3745 to get the Powerpoint versions.
Both labs require little preparation if you have standard chemical lab equipment. The PhET activities require the use of computers with Java installed. The simulations can be run online or downloaded onto the comuters in advance of the class.
PhET Interactive Simulations and the activities written by a PhET team member (which I am) are licensed under Creative Commons and may be used or adapted.