Chemistry 102 Intro. GOB Chemistry
OBSERVATION AND MEASUREMENT
Your team is employed by MegaFoods, Inc. in the quality control department.
Two new requests have just been delivered from other divisions.
Packaging wants to know if a product containing a water solution of copper
(II) sulfate (CuSO4) and table salt (sodium chloride, NaCl) will react
in any way with the aluminum can they plan to use to ship it. If so, they
need to know what happens and how to avoid it. You are asked to include
as many qualitative and quantitative observations as possible in your report.
The Juice division wants to know if their products are meeting label specifications
for USDA approval, and if the can size is appropriate (can they increase
profits by changing the juice amount or can volume?). They also need a
complete and accurate description of the juice for quality control. Since
these products are marketed globally, they need to have your measurements
and calculations in both English and metric units. Finally they plan to
market an new 8 fl. oz. product. They need to know the size of the can
needed, again in both systems. Of course, both need your report yesterday,
To make as many qualitative and quantitative observations as
possible of reactions between 2 salts and aluminum.
To recommend solutions to the packaging department for any problems.
To make qualitative and quantitative observations of a can of juice
using the metric and English systems.
To recommend a can size for the new, 8 fl. oz. product.
Bring your calculator and text to lab. Read Appendices I & II in
your text for help.
You will have metric rulers, meter sticks, centigrade thermometers,
2 juice cans per team, aluminum foil, copper II sulfate (CuSO4) and sodium
chloride (NaCl) available. Take and use the minimum amount you think you
might need. You can always get more, if necessary. Do Not return
unused portions to the stock bottles! Why not?
The following are some hints and questions to guide your work. They
are not inclusive; so you are encouraged, and indeed, expected to follow
your own ideas, as long as you consider safety issues. As with any new,
or unknown reaction, you should always start at a small scale with extra
For the Packaging Division:
For the Juice Division:
How much of each compound and in what order will it be added? How will
you know if a reaction occurs? How will you determine what caused a reaction?
Which components are essential, and which are not, for the reaction? How
can you tell?
How can you prevent a reaction from occurring? Are there consumer safety
concerns? What results of a reaction might pose a hazard inside a sealed
Are there energy changes associated with any step in the preparation? How
can you tell, or better yet, measure them? Why is this important for the
Different observers always see different parts of the same event, and even
a single observer will notice new things when seeing a repeat of an event.
How can you use this to your best advantage in reporting to Packaging?
What questions occurred to you during the tests? Which are trivial and
which are not? Which are qualitative? Which are quantitative?
Some relationships that might prove useful are listed below. If you need
something else, check your text (Appendix 1) or ask the instructor.
What information can you verify from the label on your can? What is not
verifiable? What do you recommend be done about it?
How will you verify the dimensions and volume of the can? How much juice
can it hold? How much does it hold? Is this within label
specifications? Which system allows you to be most precise? How are you
going to convert from one to the other?
What terms can be used to describe the juice? How can they be made more
precise so that everyone can agree on what they mean? What properties need
description to be complete? Again, multiple viewers/descriptions combined
are more complete.
Are consumers getting what they pay for? How much do they pay per ounce
for the juice? ... per mL or L? Are they getting mainly water? How do you
know (Hint: check the density)?
Does the expected temperature range the product may experience effect your
recommendations for can sizes?
kilo means thousand. A kilogram (kg) is 1000
To convert English units to metric equivalents, use the following:
centi means hundredth. A centimeter (cm) is 1/100th of
milli means thousandth. A milliliter (mL) is 1/1000th
of a liter (L).
A milliliter = a cubic centimeter (mL = cm3 or cc) for us.
1.000 meter (m) = 39.37 inches, 1.0 in = 2.54 cm
Converting a measured value to different units is simply a matter of multiplying
by a ratio (= 1) of the units wanted to those measured:
1.0 kilogram (kg) = 2.2 pounds, 1.0 lb. = 454 grams (g)
1.00 mL = 0.0338 fl. oz., 1.0 fl. oz. = 29.6 mL
9/5 (°C) + 32 = °F, °C = 5/9 (°F - 32), K = °C
+ 273, °C = K - 273
Measured Value x Units Wanted/Units measured
= Value in Units Wanted
For example, to convert pounds to kilograms:
The volume of a cylinder (can) = ? (r)2 height = 3.1416
(r)2 h = 3.1416 (d/2)2 h
lbs. x 1 kilogram = 79.5 kg or
mL to L: 89 mL x 1.000 L = 0.089 L
Density, useful in identifying substances (remember "Eureka!"?) and
determining what floats or sinks, is the mass in grams divided by the volume
in cubic cm (= mL):
Density (D) = Mass