2. Do substances dissolve better in water or in ethanol?
Oct 17 / Act C38
Dissolving Duel
LEARNING TARGET: I can design and conduct an investigation that uses physical properties to provide evidence to answer a given question.
CH Q
Do substances dissolve better in water or in ethanol?
VOCAB:
dissolve saturated soluble
insoluble solvent solute
Review: Solution, Mixture

3. dissolve
saturated
soluble
insoluble
solvent
solute
Process of disappearing
Holding as much water as can be absorbed (taken in)
Substance that dissolves in water
Substance that does not dissolve in water
Water that the solid dissolves in
Solid substance that dissolves

6. PROCEDURE AND DATA
MATERIALS:
PROCEDURE: Read on pg. C and summarize
DATA: Write detailed Procedure – Separate sheet of paper
WS Comparing Solubilities in Water & Ethanol
WS 38.2 What’s the Solution?

7. Lab Write Up – Format
Question: How does the solvent affect the solubility of different solids
Hypothesis: If water is used as a solvent, then more of the solid(s) will dissolve because water is a better solvent. OR
If ethanol is used as a solvent, then more of the solid(s) will dissolve because ethanol is a better solvent.

8. Variables
Manipulated Variable: Solvent used (water or ethanol)
Responding Variable: amount of solid that is dissolved
Controlled variables: everything else
Materials
See page C-43

9. Procedure (hints) Do procedure for water first
Use Data table to help guide amounts of solutes and solvents
Identify which ‘sepup’ cups each item is to go into. (7 ingredients – 7 steps) (ie: place 1 scoop sugar into cup 4)
Make sure to clean (wash/dry) scooper between each solute/solvent change
Make sure to clean (wash/dry) sepup tray prior to ethanol experiment
Then say ‘repeat steps for ethanol’
Clean Up – None can go down sink. Use paper towel to scoop into the trash – then wash and dry and repeat for ethanol (or final clean up)

10. Claim: Water was the best solvent.
Conclusion
Write conclusion in a C-E-R format. Make sure you use evidence from the data you took during the lab.
Claim: Water was the best solvent.
Evidence: Water was able to dissolve 3 of the solutes. Ethanol only dissolved 2 solutes.
Reasoning: Water was the better solvent because it dissolved more solutes.

11. Lab Write up - Conclusion
My hypothesis was, if water is used as a solvent, then more of the solid(s) will dissolve because water is a better solvent.
Water was able to dissolve 3 of the solutes. Ethanol only dissolved 2 solutes.
My hypothesis was correct because water dissolved more solutes than the ethanol.

12. ANALYSIS
- Discuss and answer Q 2 & 5 on pg. C 45
ANS CH Q
Do substances dissolve better in water or in ethanol? A:
Better in water
HOMEWORK
Finish AQ’s
WS 38.2
Quiz on Monday!
Vocab packet due
WS due