Following from our study of equilibrium constant and solubility product, we are conducting an experiment involving (1) burning magnesium, (2) collecting the magnesium oxide that results, (3) mixing it with water to form magnesium hydroxide, (4) adding acid to convert the magnesium hydroxide to a magnesium salt, (5) evaporating the liquid and (6) weighing the residue to determine what is in the salt. Through it all, weighing and the mole concept are important concepts to be mastered. The questions to be considered and the points involved in metacognitive analysis of the experiment are:
1. What is an acid?
2. What is a base?
3. You react Mg with O2 in the air. What kind of reaction is that?
4. What is the product of the reaction? Write it out and balance the reaction equation.
5. You want to collect and quantify the product of the reaction. How is this done?
6. After you collect the reaction product, you try to dissolve it in water. The solubility product is Ksp = 1.5 x 10-11. What does this tell you about the solubility of the product of the reaction?
7. You test the solution with a piece of pH paper. The color indicates a pH between 8 and 9. What is the best accuracy you can say for the pH?
8. If you heat the solution, you think you have more reaction product dissolve. What is a way to determine this? What chemical principle would allow this way to work?
9. To convert the reaction product into a sulfate or chloride salt, you can add drops of sulfuric or hydrochloric acid. What is the formula for each of those acids?
10. Write the reaction between the reaction product (in water) with the acid, and balance the chemical equation for the reaction.
11. The acid solutions you have are 1 M. What does this mean?
12. What is your evidence that a reaction between the acid and the reaction product has occurred?
13. You need to convert the number of drops of acid you added to your reaction product solution into milliliters. How is this done?
14. You want to calculate the “yield” of the oxidation of the Mg. What did you do?
15. You want to verify your work by calculating the amount of acid that reacted with the reaction product. How did you do this?
16. You can evaporate the liquid from the salt that formed when the acid reacted with the reaction product and weigh the residue. How do you do this? What measurements do you need to make? What equipment do you need?
17. What are the names, common or scientific, for the salt that results?
18. What chemistry principles have you learned from this experiment? (Think of acids and bases, equilibrium, balancing equations, etc.)
No comments:
Post a Comment