LAB- CHEMYSTERY: SPARKLE-CLEAN VS. BUBBLES
(PHYSICAL VS. CHEMICAL PROPERTIES/QUAL SCHEME)
Purpose: To use chemical and physical properties to identify the unlabeled chemical bottles
at Sparkle-Clean Industries.
CheMystery:
Sparkle-Clean Industries is presently in the process of expanding their product line. In the
past they have focused on such items as air fresheners, carpet cleaners, and deodorizing
cleansers. They are now interested in producing a new line of fresh smelling body soaps.
Bubbles, Inc. is the major producer of body soaps on the East Coast and Sparkle-Clean is
hoping to win over some of those customers with this new product line. In an act of revenge
someone broke into the warehouse of Sparkle-Clean late last night and ransacked the
chemical supply room. Investigators believe it may be the work of a disgruntled former
employee of Sparkle-Clean. This employee now works for the competitor; Bubbles, Inc.
Labels were torn from several chemical bottles and strewn on the floor. A worker arriving
early this morning was able to salvage several of the chemicals and their labels. Help to
identify the unlabeled chemicals.
Background:
Physical properties can be measured or observed without changing the chemical
composition of a substance. Physical changes occur when the arrangement of particles in
a material changes. Dissolving, boiling, melting, evaporating, powdering, tearing, and
crushing a substance are all examples of physical changes.
Chemical properties describe how a substance reacts to form new substances with new
chemical and physical properties. Chemical changes occur when substance(s) undergo
chemical reactions and change in chemical composition to form new substances. For
example, all carbonates react with vinegar to form carbon dioxide gas. Other chemical
changes include rusting, burning, corroding, and any chemical reaction.
The flow chart on the next page may be used to identify 6 different substances based on
differences in their chemical and physical properties.
Flow Chart for Identifying the 6 Substances
Cornstarch, Table salt, Epsom salt, Washing soda, Plaster of Paris, Chalk
Add water
Soluble (solution part looks clear)
Insoluble (mixture looks milky/cloudy)
Table salt, Washing soda, Epsom salt
Cornstarch, Plaster of Paris, Chalk
Add
Phenolphthalein
Not Pink
Table Salt or
Epsom Salt
Pink
Washing
Soda
Add NaOH
Clear Pink
Table Salt
Add
Iodine
Yellow
Chalk or
Plaster of Paris
Black
Cornstarch
Add vinegar
Cloudy
Pink
Epsom Salt
Fizzes
Chalk
Doesn’t fizz
Plaster of
Paris
Safety Information:
1. Always wear goggles, an apron, and appropriate shoes while working in the lab.
2. Assume all chemicals are toxic by ingestion and inhalation. Assume they are skin and
body irritants. Do not touch or taste the compounds.
3. Do not perform any additional tests without the consent of the instructor.
Procedure for Identifying Known Compounds:
Read the entire procedure before beginning the experiment!
1. Clean 6 test tubes and label them from 1 to 6.
2. Data Table #1 on the next page lists the compounds you will need.
3. Use a spatula to put a pea sized sample of compound 1 into test tube 1.
4. Use a spatula to put a pea sized sample of compound 2 into test tube 2.
5. Repeat for compounds 3 – 6.
6. Follow the flow chart, beginning by adding about 3 mL of water to each test tube. Stir
with your stirring rod to determine if the compound dissolves in water. Record results
in Data Table #1. Be sure to clean off your stirring rod each time you put it in a
different compound.
7. To the test tubes of the compounds that are soluble in water, add 1-2 drops of
phenolphthalein and record the results.
8. To the test tubes of the compounds that do not turn pink in phenolphthalein add 2-3
drops of NaOH and record the results.
9. To the test tubes of the compounds that are not soluble in water, add 1 drop of iodine
and record the results.
10. To the test tubes of the compounds that do not turn black with iodine, add about 1
milliliter vinegar and record the results.
11. Dump the contents of each test tube down the drain one at a time with plenty of
running water. Clean up and return all materials to their proper place.
Directions: In the data table below, write your observations in the appropriate boxes.
Data Table #1: Identifying Known Compounds
Name
of
Compound
Soluble
In
H2O?
Reaction
with
Phenolphthalein
Reaction
With
NaOH
Reaction
with
Iodine
Reaction
with
Vinegar
(soluble looks
clear
vs.
insoluble
looks cloudy)
(not tested,
pink,
or not pink)
(not tested,
clear pink,
or cloudy
pink)
(not tested,
yellow, or
black)
(not tested,
fizzes, or
does not
fizz)
1 – Cornstarch
(---)
2 – Table Salt
(NaCl)
3 – Epsom Salt
(MgSO4)
4 – Washing Soda
(Na2CO3)
5 – Plaster of Paris
(CaSO4)
6 – Chalk
(CaCO3)
Procedure for Identifying Unknown Compounds:
1. Repeat the procedure substituting the unknown compounds for the known compounds
2. Record all results in Data Table #2 on the next page.
Data Table #2: Identifying Unknown Compounds
Unknown
Soluble
In
H2O?
Reaction
with
Phenolphthalein
Reaction
with
NaOH
Reaction
with
Iodine
Reaction
with
Vinegar
(soluble
looks clear
vs.
insoluble
looks
cloudy)
(not tested,
pink,
or not pink)
(not tested,
clear pink,
or cloudy
pink)
(not tested,
yellow, or
black)
(not
tested,
fizzes, or
does not
fizz)
Identity
(Name)
Of
Chemical
A
B
C
D
E
QUESTION:
1. Describe anything in the experiment that might have went wrong or could have
caused error in your results. Include at least 2 possible sources of error. Be specific.
__________________________________________________________________
__________________________________________________________________
__________________________________________________________________
2. Differentiate between physical properties and chemical properties.
__________________________________________________________________
__________________________________________________________________
3. Example of physical property ___________ Example of chemical property __________
4.
Na2CO3, Pb(NO3)2, ZnSO4, NaOH, Na2S2O3, KI, NaCl, BaCl2
Litmus Paper (wet)
Basic
Acidic
Neutral
Na2CO3, NaOH, Na2S2O3
H2SO4
Yellow
ppt.
Bubbles
White
ppt.
KI
NaOH
Pb(NO3)2, ZnSO4
AgNO3
HCl
Soluble
KI, NaCl, BaCl2
Yellow
Precipitate
e
Na2CO3
White
ppt.
Soluble
BaCl2, NaCl
ZnSO4
Pb(NO3)2
H2SO4
White
ppt.
Soluble
Na2S2O3
NaCl
BaCl2
4a. What substance would have had the following results?
neutral & upon adding AgNO3 a yellow precipitate formed ____________________
4b. What substance would have had the following results?
basic & upon adding HCl there were bubbles ______________________________
4c. What substance would have had the following results?
acidic & upon adding H2SO4 a white precipitate formed ______________________
4d. What tests / results would have to be completed to determine if a substance was BaCl2?
_____________________________________________________________________
_____________________________________________________________________