Do substances dissolve better in water or in ethanol? Oct 17 / 18 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

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

PROCEDURE AND DATA MATERIALS: PROCEDURE: Read on pg. C 42-44 and summarize DATA: Write detailed Procedure – Separate sheet of paper WS 38.1 Comparing Solubilities in Water & Ethanol WS 38.2 What’s the Solution?

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.

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

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)

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.

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.

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