1. Activity 37 Analysis
In this investigation, which substance(s) are solutes and which are solvent(s)?
Sodium chloride and copper chloride are solutes
Water is the solvent each time
Part of iron chloride is the solute (water turned a clear brownish color), most didn’t dissolve
Cornstarch was not a solute

2. A substance that dissolves in water can be described as soluble in water
List the four solids in order from most to least soluble in water.
Explain what evidence enabled you to order the substance by solubility
Copper chloride, sodium chloride, iron chloride, cornstarch
All 5 scoops of copper chloride dissolved in the water
Liquid in the filter remained light blue
1 scoop of sodium chloride dissolved completely & not quite all of the 5 scoops did
Iron chloride is only slightly soluble; water became slightly brown and most remained solid; stayed in the filter
Cornstarch least soluble; appeared to mix in but settled out if it sat; amount in the filter looked like original amount; liquid was clear after filtering (milky white before)

3. a. Must a liquid be clear to be a solution? Explain.
Yes
If it isn’t clear, there are still large particles in the mixture
Must a mixture be colorless to be a solution? Explain. No
Copper chloride completely mixed in and it was blue
It’s a solution even if it has color

4. Imagine that all four of the tested solids are considered water pollutants. Which would be easiest to remove from the water? Explain.
Cornstarch
Particles don’t dissolve; can be removed with a filter
Most of the iron chloride could be removed with a filter

5. Design your own experiment
In activity 38, you will write your own procedure and design a data table to collect the data.
You are going to test the ability of several different solids to dissolve in two liquids: ethanol and water
What are the solvents?
What are the solutes?

6. Title: Dissolving Duel
Activity 38
Title: Dissolving Duel

7. Read C-43
Problem: Do substances dissolve better in water or in ethanol?
Hypothesis:
Fill in the chart below and check the box under the solvent you think will work better to dissolve the material.
Substance
Dissolve better in water
Dissolve better in ethanol
Cornstarch
Lauric Acid
Sugar
Copper Sulfate
Sodium Chloride
Neronline Yara Yara
Iron Chloride

8. Design a procedure & data table
Use the procedure in activity 37 as a guide
Make sure your experiment is reproducible (someone could read your procedure and do it exactly as you did---don’t leave any steps out)
The purpose is to compare the solvents, consider whether you need to vary the number of scoops you use for each solute.
Design a data table
What type of results are important to record?

9. Work in your group on a separate sheet of paper (one person write it) to brainstorm ideas and steps for your procedure
Do not write your procedure or data table in your notebook until it has been approved by your teacher
Think of a way to minimize the amount of each solvent and solute you use
Compare your procedure with other groups to get feedback

10. Sample Procedure
Decide which team of two will use water as the solvent and which will use ethanol.
Place one level scoop of each solute in the appropriate cup (as listed in the table).
Add 10 drops of your team’s solvent to each cup.
Use the stir stick to stir each cup for 30 seconds. Clean the stick after stirring each substance.
Record your team’s observations in your data table.
Trade trays with the other team, and record your own observations of their mixtures in your notebook data table.

11. Data/Observation: Table: Comparing Solubilities in Water and Ethanol

12. Or two tables:

13. Results: