What's That Smell? Demonstration
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ward
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science
Recommended Grade Level(s):
Appropriate for: High School or College
Time Requirements:
Prep Time: 10–15 minutes
Activity Time: approx. 45 min. to 1 hour depending on how many esters are created.
Teaching Topics & Concepts:
• This procedure illustrates the variety of odors that are produced from esters
• Connections to: Organic synthesis, and condensation reactions
Materials:
• Organic alcohols in dropper bottles (see chart below for suggestions)
• Organic acids in dropper bottles (see chart below for suggestions)
• Sulfuric acid H2SO4 (18 M)
• Sodium carbonate, Na2CO3
• Test Tube Holder
• Test Tubes
• Bunsen Burner
Safety
• Concentrated acids are used. Read the SDS for all chemicals before using them
• Wear safety glasses, gloves and lab coat or apron.
• Waft vapors when detecting odors—do not sniff directly from vessel
!
Procedure:
1. In a test tube, add 15 drops of Ethanol to 20 drops of glacial acetic acid.
2. Add one drop of concentrated sulfuric acid
3. Mix the reactants by gently tapping the test tube
4. Gently heat the bottom of the test tube for several minutes
a. Keeping the test tube on a slight angle helps control vapor loss.
b. If solution starts to boil, remove from heat
5. Carefully smell by wafting. Dilute with water if the smell is still too strong.
6. See the chart for more combinations. Use 0.5g of solid acids such as salicylic acid.
Expected Results:
Results may vary based on materials used, setup, procedure, and other factors, however, here are a few examples on what to expect:
• Following this procedure will allow you to create various familiar smells by mixing the appropriate acids and alcohols.
Find materials for this activity at wardsci.com.
Discover more free activities at wardsworld.wardsci.com
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