Part 1: PRE-LAB: ELEMENTS
& COMPOUNDS USED IN EVERYDAY LIVING
At home collection of lab data (5 points)
ELEMENT INVENTORY: Find examples of as many elements and
compounds as possible in the entire Periodic Table. Look at the
ingredient's lists on foods, drugs, and other house hold items.
Baby formula has about 15 elements listed. Look for the names
of the chemicals that seem to have the name of a chemical element
as part of the name. There are many names which you will not recognize
- simply ignore them. In other cases you may list the names of
compounds and elements which you know from common knowledge such
as gold and silver in jewelry.
Do not make duplicates in element
names or symbols, but make a fairly exhaustive listing because
we will use the list for several activities such as writing the
formula. Each element may be listed only once, even though you
may find it numerous times. Make the following Element
Inventory Table :
EXAMPLE INVENTORY TABLE
On the far right side for the element count, simply count how
many different elements have been found, count only one example
of each element. For example in water are the elements hydrogen
and oxygen. In Baking Soda, the elements sodium and carbon are
found. In air, nitrogen and oxygen are found, but do not list
oxygen a second time, list nitrogen instead. From these three
substance five elements are counted.
Dr. O Help: More Examples
This element inventory listing
is worth 5 points if you find 30 elements. 25 elements = 4 points;
20 elements = 3; 15 or less elements = 2.
QUES. 1: Make the following
Element Inventory Table :
(It is not necessary to make a
fancy table, you may just use spaces following the headings below.)
Count, Common Substance, Chemical
Name, Element Name, Element Symbol
1, water, -, oxygen, O
2, water, -, hydrogen, H
Chemical and physical
properties can be used to help identify compounds in solids such
as, sodium carbonate, sodium bicarbonate, sodium chloride, calcium
carbonate, and sodium hydroxide. The compounds to be tested for,
as well as, all the reagents used to identify them are readily
available in most drugstores, supermarkets, or variety stores.
The tests require no more than a few small cups, a measuring cup,
an eye dropper, and a spatula or measuring spoon.
The chemicals are all available as household products. The white
solids to be used in this lab are listed in Table 1 along with
their sources. These substances can be taken directly from their
packages, except for the calcium carbonate which must be powdered.
You will need a minimum of 3 compounds or mixtures from the
list below plus 2 where online data are given (Epsom salt and
Compound Name, Formula, Source of Compound
Sodium chloride, NaCl, Plain table salt
Sodium bicarbonate, NaHCO3, Baking soda
Sodium carbonate, Na2CO3, Washing Soda Detergent e.g. Arm &
Calcium carbonate, CaCO3, Calcium supplement tablets (TUMS)
Sodium Aluminum dihydroxide carbonate, NaAl(OH)2CO3, ROLAIDS
Any solid detergent
Any solid antacid
PART 2: PHYSICAL PROPERTIES AND CHANGES
Combination of online and at home collection of data (6 points)
is to do five compounds total - use any 3 of the above compounds
or mixtures, plus 2 compounds given online for full credit.
O r do five compounds of your own.
(Minus 1/2 point for each not done.)
Proc. 1: Solubility Tests:
Each of the five solids is first tested for solubility in water.
To perform the solubility test, use a spatula or knife tip to
obtain less than an aspirin tablet sized amount of material, (too
much solid will obscure the results) and place it in a small cup
with about 1-2 teaspoons (5 ml) of water. Do this with all three
of the solids in separate cups. Mix and stir well for several
minutes to see whether the solid will dissolve, if necessary add
more water. SAVE the solutions for further testing.
Try to distinguish between complete
dissolving - clear solution - These are called SOLUBLE;
to almost dissolved - may have a slight cloudiness left- listed
as partially SOLUBLE;
to lots of solid remaining, very cloudy - listed as INSOLUBLE.
Dr. O, Help!
Compounds that dissolve in water undergo a physical change.
The chemical formula remains intact. If the water is evaporated,
the original compound is recovered.
Online data for: These two count for 2 of the five required
Record the observation results
in a table format as follows. Dr. O, Help!
QUES. 2: OBSERVATION TABLE for Solubility Tests
On the Observation Table record the
observations and results of the tests. For each compound
or mixture tested, record the name, and the formula
(if given), any significant observations - what did you see???,
and results or conclusion of the test based upon the observation.
Example: Aspirin; (formula not given); white solid dispersed
in water, milky, some particles float; result = insoluble.
Results for five more samples:
Dr. O, Help!
QUES. 3: Match definitions and examples:
Proc 2: Evaporation
of a Solution:
Do the following procedure on ONE of the solutions that is soluble
or almost soluble, such as the salt or sugar solution. Pour the
solution into a metal sauce pan and evaporate the water using
the the burner on the stove. After the water has been evaporated
to dryness , a residue should remain. DO NOT OVER HEAT - AS THE
SUGAR MIGHT BURN. After the pan has cooled, you might try the
taste test to identify this residue. Moisten your finger, touch
the residue, and cautiously taste it.
QUES. 4: A physical change occurs when the composition of
a substance remains the same. (True or False)
QUES. 5: A chemical change occurs when the composition of
a substance remains the same. (True or False)
QUES. 6: Evaporation is is an example of a chemical change.
(True or False)
QUES. 7: Salt or sugar dissolving in water is a physical
change. (True or False)
Proc. 3. MIXTURE OF LIQUIDS
- A SIMULATED OIL SPILL
QUES. 8: The oil stay on the bottom of the water. (True
QUES. 9: The oil is more dense than the water. (True or
QUES. 10: Solubility behavior and density behavior of oil
and water is: a chemical or physical property ?
QUES. 11: a) Devise a method to remove the oil from
the top of the water. Available devices are eye droppers to simulate
a vacuum type device, paper towels, pieces of cotton balls, detergent,
anything else that you can think of. Carefully record and describe
which methods were used to separate the oil from the water.
b) Would the method that you used to clean up
an oil spill have any applicability on a large body of water such
as a river or ocean? Explain.
PART 3. Chemical Reactions
****All Data for Part
3 is given online****
****You do not actually
have to complete these procedures. Dr. Ophardt did them for you
and took pictures of the results. You should read the procedures
to see what was done, record the data, and answer the questions.*****
Procedure 1: WHICH METALS REACT
Did you know that pennies come
in two varieties? Pennies minted before 1982 are made entirely
from the metal element called copper. Pennies minted after 1982
contain a core made from the metal element zinc and the outer
layer is made of copper. In this experiment, you will discover
the chemical properties of zinc and copper metals, with hydrochloric,
HCl, from Sno Bol toilet bowl cleaner.
1. First use a wire cutter
type pliers or an old scissors to make five or six very thin cuts
on the edges of a 1983 (or newer) penny. Or use a file to remove
small amount of copper metal from the edges of the pennies. The
cuts should expose a silvery metal which is zinc beneath the copper
3. Prepare one cup and fill half
full with Sno Bol toilet bowl cleaner (use the thin rather than
the thick variety if possible) or any other toilet bowl cleaner,
which contains hydrochloric acid.
4. Next put the one penny into
the small plastic cup containing the Sno Bol toilet bowl cleaner.
5. Make and record observations
during the first few minutes. Look for bubbles of hydrogen gas
coming from the edges of the penny or the aluminum foil. Are the
gas bubbles coming from the copper metal or the zinc metal or
the aluminum metal?
6. This chemical reaction of the
acid with the penny takes several days to complete.
OBSERVATIONS AND RESULTS on
metals with acids:
Write details of the observations,
both immediately and after 1 or 2 days.
Bol + penny
QUES. 12: Which metal copper or zinc reacts with
the hydrochloric acid?
QUES. 13: Which metal copper or zinc do not react
with the hydrochloric acid?
This shows that metals may have
different chemical properties towards the acids.
QUES. 14: What is the name of the element in the
gas bubbles? Oxygen, Hydrogen, Chlorine
These observations are an example
of a chemical properties and reactions. Various elements in the
original substances undergo a chemical reaction where elements
in compounds rearrange and change "forms" - metals into
ions; and ions into the element form.
The outside coating of copper
metal does not react with hydrochloric acid, HCl, in the
toilet bowl cleaner. The zinc metal core does react
with the acid, hydrogen ions, H+, to produce zinc ions, chloride
ions, (which are invisible in the water) and hydrogen gas bubbles
(which escape into the air). The element zinc metal turns into
soluble zinc ions. The final result is a "hollow"
penny. Two elements change form: zinc metal changes to zinc
ions and hydrogen ions change into the diatomic hydrogen gas form.
Cu metal + HCl ===> No reaction
Zn metal + 2 HCl ===> Zn+2
ions + 2 Cl- ions + H2 gas
Procedure 2: Reaction of Zinc
Reaction Graphic of zinc and iodine
The reaction in this case is between
two elements, zinc metal and iodine. Both look sort of grayish
in the photo. The reaction is started between the dry powders
by adding a few drops of water. The reaction occurs as a combination
reaction between the two elements to produce a single compound.
During the reaction zinc metal gives two electrons to two iodine
atoms to produce zinc +2 ions and iodide -1 ions.
The reaction is: Zn metal + I2
The reaction between the two elements
to produce zinc iodide is very exothermic. Some of the unreacted
iodine solid is heated to a gaseous iodine which is purple in
QUES. 15: A molecule is only defined as the simplest
part of a compound with two or more atoms. (True or False)
QUES. 16: For an exothermic reaction, heat is given off in
the process. (True or False)
QUES. 17: The fact that unreacted iodine changes to gaseous
iodine is a: chemical or physical change?
Procedure 3: Reaction of Efferdent
and Alka-Seltzer with Water
Graphic of Alka-Seltzer
Graphic of Efferdent
The reactions in both of the above
cases start when a solid tablet is dropped into water. The chemicals
in dry solid form must dissolve in the water before a reaction
may take place. In both cases gas bubbles are observed. A flaming
or glowing splint is used to test for the identity of the gases.
Alka-Seltzer: (Baking soda or
sodium bicarbonate) NaHCO3 + Citric acid ---> CO2 + H2O + Sodium
Efferdent: (sodium perborate - a source of hydrogen peroxide)
= H2O2 + catalyst ---> O2 + H2O
QUES. 18: Define chemical property. Then use this
definition to describe the difference in behavior toward the falming
splint for both gases in the above examples.
QUES. 19: Graphic
of Baking Powder - Revisited
Based upon the observations in
the graphic, do you think that putting baking powder in water
represents a physical or chemical change? Explain your answer.