Name: ______________________________________ Date: ________________________
Student Exploration: Mystery Powder Analysis
Vocabulary: Biuret solution, iodine solution, litmus paper, vinegar
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
A white powder is found spilled on the kitchen floor of a crime scene. A similar powder is found
on the shoes of a suspect in the crime.
1. What are some powders that you might find on the kitchen floor? _____________________
_________________________________________________________________________
2. How could you tell if the powder was salt, sugar, flour, or baking soda? ________________
_________________________________________________________________________
Gizmo Warm-up
The Mystery Powder Analysis Gizmo™ allows you to use a
variety of tests to identify unknown substances. To start, drag
the Baking soda test tube into the “Place tube here” area.
1. Under Appearance, click Test. Is baking soda a fine
powder (no visible grains), or is it coarse (visible grains)?
_____________________________________________
2. Litmus paper is an indicator of acids and bases. Under Litmus test, click Test. Which
of the following results occurred? (Circle the answer.)
A. Both strips red (acid) C. One red, one blue strip (neutral)
B. Both strips blue (base)
3. Some substances react with vinegar to produce carbon dioxide, visible as bubbles.
Under Vinegar test, click Test. Does the vinegar bubble? ________________________
4. The blue Biuret solution turns bright purple in the presence of proteins. Iodine
solution turns dark purple in the presence of starch. Try each of these tests.
Does baking soda contain protein? ______ Does baking soda contain starch? ______
Hannah Sonnentag
12/15/11
salt, flour, sugar, baking soda, garlic powder,
You take samples and taste them.
it a coarse grain that is visible
yes
yes
no
