Apologia: Chemistry Moles

The Chemistry class began today's lesson with a mole activity.  They are working on the POGIL  ChemActivity 27. (Here is the Mole ChemActivity 27 Answer Key) over the Thanksgiving Break.

Today, I had the kids weigh moles, first.  Sounds stupid, right?  It helps!  I had the kids calculate the molar mass for copper (II) sulfate penta hydrate, magnesium sulfate hepta hydrate, sodium bicarbonate, water, and salt.  You can give them just the formulas or names to add a little nomenclature.  Once they calculated their respective molar masses and weighed the chemicals, the kids made 1M or one molar solutions of each compound.  I did not want liters of each solution.  Instead the class made 1 M solutions by dissolving 0.1 moles of each compound in 100 mL of water.  (If you have your class make solutions, be sure to explain they need to dissolve the salts in about 50 mL of water and then add enough water to make 100 mL total.  If they add the salts to the 100 mL of water, the solution will not be exactly 1M.). The Physical Science class used these solutions for their precipitate lab.  We also spent time reviewing last week's hydrate lab and the lab on metal reactivity.  I had the kids calculate the theoretical yields for each hydrate before determining their experimental yields.  Once they had both calculations, they determined the percent error.  The error was high because they had not heated their hydrates long enough to remove the water from the compound.  The Percent Composition of Labs is quite similar to  Mini-lab Percent Composition we used.  The kids used 5-10 grams of Epsom salt and copper (II) sulfate hydrates last week.  They heated them using test tubes and an alcohol burner.  They should have heated the salts longer. Lastly, we practiced balancing equations, especially combustion equations and those with polyatomic ions.  Balance Equations with Polyatomic Ions