1. You work for a crafts supply company, KidKrafts, makingcalcium carbonate for their chalk products. They have recentlydecided to add plaster of Paris as one of their products. The keyingredient in plaster of Paris is calcium sulfate (CaSO4). You havebeen asked to adapt your knowledge of making calcium carbonate fromcalcium chloride dihydrate (CaCl 2 •2H2O ) and anhydrous sodiumcarbonate (Na2CO3) to making calcium sulfate. To make the mostprofit, you will be using the same stock of calcium chloridedihydrate as for the chalk. Therefore, you need to make sure thatyou use only the necessary amounts of each reactant. Your boss hasasked you to not only figure out how to make the calcium sulfatebut to prove that you don’t have any excess of either reactant.
a. The first step is figuring out what you need to mix togetherto make calcium sulfate. You know that the combination of calciumchloride and sodium carbonate worked well to make calcium carbonatein lab. Propose one chemical that you could react with calciumchloride to make calcium sulfate.Give two reasons why the chemical you chose willwork. (Hint: What can you replace sodium carbonate with to makecalcium sulfate instead of calcium carbonate?)
b. Now that you’ve selected a reactant, write out its (a)complete and (b) net ionic reaction with calcium chloride. You canignore the waters of hydration on calcium chloride for thisstep.
c. If you run the reaction above using a solid mixture ofexactly the right amount of each reactant, how can you prove thatthere is no excess? Describe the steps involved with this test.(Hint: Think about how you determined which reactant was in excessin the lab.)
d. Since you are developing a new procedure with a new chemical,you need to check how will you store it at the lab. Look up theMSDS of the reactant you proposed. What does your boss need to keepin mind when storing this chemical?
e. To try out your reaction and test for correct amount, youfirst need to determine how much of the reactants you need. Whatmass of your proposed reactant will you need to react with 1.000 gof calcium chloride dihydrate?
