MHS Chemistry
Continuous Variation (Cu & S)

Part 1 - Setup
Each student must complete this section before working with any chemicals in this lab.
my partner is: _________________________
name of compound: _________________________
goal concentration: _________________________ _____
volume of solution to make: _________________________ _____
chemical formula for compound: _________________________
molecular weight of compound: _________________________ _____
moles required: _________________________ _____
mass of solute required: _________________________ _____

Show your calculations to find the mass of solute.  Remember to use the factor/label method, and don't round anything off until the final result.

Part 2 - Combination
After you and your partner have made your solutions, record your observations of the individual solutions.  Record the color, smell, and results of testing with blue litmus and red litmus paper.
Solution name: _________________________ _________________________
color: _________________________ _________________________
smell: _________________________ _________________________
red litmus paper ® _________________________ _________________________
blue litmus paper ® _________________________ _________________________

After recording your observations, gently mix the two solutions in a flask large enough to hold the combined volume.  Write your name (in pencil) on a piece of clean, dry filter paper, and record it's mass.  Then carefully filter your solution to collect the solid ("residue").  Do not discard the liquid that passes through tht filter paper ("filtrate").
mass of filter paper: _________________________ _____
color of filtrate: _________________________
smell of filtrate: _________________________
filtrate + red litmus paper ® _________________________
filtrate + blue litmus paper ® _________________________
mass of filter paper  + residue: _________________________ _____
mass of residue: _________________________ _____

Part 3 - Analysis
Gather data from the rest of the class to complete a data table with the following headings:

    volume of copper (II) sulfate pentahydrate            mass of residue (g)                            source of data

When you have completed the table, you will produce a graph of the data.  The rest of the instructions for this lab will be presented in class.

[Continuous Variation Lab score sheet][MHS Chem page]