MHS Chemistry
Continuous Variation (Cu & S) score sheet
Title: 1. "Determination of the Formula of Copper Sulfide" + The usual title page stuff
Purpose: (Translate the following to the first person point-of-view)
2. Calculate the mass of a specific chemical to make an assigned solution, and make the assigned solution.
3. Gather data from the classes to
4. Determine the ideal combining ratio of copper (II) sulfate pentahydrate with sodium sulfide.
5. Use the ideal combining ratio to determine the formula for copper sulfide and...
6. Write the complete balanced equation for this reaction.
Assigned Dataxxx 7. What chemical?  What volume?  What Concentration?  (see Part 1 - Setup)
Calculation 8. Show how you determined the mass of your chemical.  Use the factor label method.  This is also on the handout you got for part 1 in class
Data/Results 9. The mass of chemical you needed for your solution.
10. The mass of copper sulfide produced.  Include any data you used to calculate this amount.
11. A graph of product mass (y, in grams) and volume of copper (II) sulfate solution (x, mL).  On the same graph, along the top, label an extra x-axis by indicating the ratio of moles of copper (II) sulfate to moles of sodium sulfide.  The ratios should all be 1:? or ?:1.  The graph should be landscape and fill the page.
12. Indicate your selection of the best combining ratio of the two reacting chemiclas.
13. A balanced chemical reaction based on your ideal combining ratio.  The formula for copper sulfide is CuxSy with x and y coming from your combining ratios.  Getting this formula is part of your results, so think very hard.
Neatness 14. This lab must be neat.  I like typing J

That's 14 pieces to grade, each 0-4.
0 No attempt, missing, or copied
1 Tried but missed
2 Close, but no cigar
3 Good job, no frills
4 Excellent, neat, creative, over the top, wonderful, leather trim AND CD-player.

[Continuous Variation lab][MHS Chem page]