Oakland Schools Chemistry Resource Unit
Nomenclature & Chemical Reactions Lynn Hensley
South Lyon High School
South Lyon Community Schools
1
Nomenclature and Chemical Reactions
Content Statements:
C4.2 Nomenclature
All compounds have unique names that are determined systematically
C4.2x Nomenclature
All molecular and ionic compounds have unique names that are determined
systematically.
C3.4 Endothermic and Exothermic Reactions
Chemical interactions either release energy to the environment (exothermic) or absorb
energy from the environment (endothermic).
C5.2 Chemical Changes
Chemical changes can occur when two substances, elements, or compounds interact
and produce one or more different substances whose physical and chemical properties
are different from the interacting substances. When substances undergo chemical
change, the number of atoms in the reactants is the same as the number of atoms in
the products. This can be shown through simple balancing of chemical equations. Mass
is conserved when substances undergo chemical change. The total mass of the
interacting substances (reactants) is the same as the total mass of the substances
produced (products).
C5.5 Chemical Bonds-Trends
An atom’s electron configuration, particularly of the outermost electrons, determines
how the atom can interact with other atoms. The interactions between atoms that hold
them together in molecules or between oppositely charged ions are called chemical
bonds.
C5.6x Reduction/Oxidation Reactions
Chemical reactions are classified according to the fundamental molecular or sub
molecular changes that occur. Reactions that involve electron transfer are known as
oxidation/reduction (or “redox”).
2
Content Expectations:
C4.2A - Name simple binary compounds using their formulae.
C4.2B - Given the name, write the formula of simple binary compounds.
C4.2c - Given a formula, name the compound.
C4.2d - Given the name, write the formula of ionic and molecular compounds.
C3.4A - Use the terms endothermic and exothermic correctly to describe chemical
reactions in the laboratory.
C5.2A - Balance simple chemical equations applying the conservation of matter.
C5.5B - Predict the formula for binary compounds of main group elements.
C5.6b - Predict single replacement reactions.
3
Instructional Background Information:
Nomenclature/Chemical Bonds:
Nomenclature involves the naming and formula writing for molecular and ionic
compounds. Molecular compounds are limited to two nonmetals using the first 20
elements. Ionic compounds are limited to the first 20 elements plus copper, iron, lead,
and mercury and common ions. Common ions are limited to: acetate, hydroxide,
sulfate, sulfite, nitrate, nitrite, carbonate, and ammonium. See examples below:
Ionic Compounds
Type 1
Name the metal, then name the nonmetal-but change ending to ide
Ex. NaCl
AlF3
sodium chloride
aluminum fluoride
Type 2
Name the metal, and then name the polyatomic ion
Ex. NaNO3 sodium nitrate
Li3(PO4) lithium phosphate
Type 3
Transition metals must include charge as a Roman numeral. This is the stock
system.
Ex. Fe2O3
CuCl
CuCl2
iron (III) oxide
copper (I) chloride
copper (II) chloride
4
Binary Molecular Compounds
Usually consists of 2 nonmetals. Names use prefixes to indicate subscripts.
Names still use –ide endings
1=mono
2=di
3=tri
Ex. CO
N2O4
PCl3
SCl6
N2O3
carbon monoxide
dinitrogen tetraoxide
phosphorus trichloride
sulfur hexachloride
dinitrogen trioxide
4=tetra
5=penta
etc.
Writing Formulas – Ionic Compounds
Steps:
1) Write symbols for each ion.
2) Determine charge of each ion.
3) Add more of either ion, as needed in order to get a neutral charge on the
compound.
4) Put parentheses around polyatomic ions.
5) Subscripts indicate the number of each ion used.
EX: calcium iodide
Ca
I
Ca+2 I-1
CaI2
EX: aluminum sulfate
Al
SO4
Al+3 SO4-2
Al2(SO4)3
Endothermic and Exothermic Reactions:
Use the terms endothermic and exothermic to describe chemical reactions in which heat
is transferred between the system and surroundings. Possible demos/reactions include
zinc or magnesium with hydrochloric acid or steel wool with vinegar for exothermic.
Endothermic reactions would be vinegar with baking soda or ammonium chloride with
barium hydroxide.
Reactions either release or absorb energy based on the net energy change of the
bonds.
5
Chemical Changes:
Balance chemical equations using coefficients to obey the law of conservation of matter.
Teacher tip: Use the acronym MINOH for ordering of balancing. Order: Metals,
polyatomic Ions, Nonmetals, Oxygen, Hydrogen. Draw representations of chemical
equations using shapes to map out the reactants and products.
EX: 2 H2 + O2 Æ 2 H2O
□□ + □□ + ●●Æ □●□ + □●□
Reduction/Oxidation Reactions:
These reactions involve the transfer of electrons between two elements. Single
replacement reactions are prime examples of these. The use or development of an
activity series to predict which reactions actually occur is necessary. Keep in mind that
metals replace metals and nonmetals replace nonmetals. The element higher on the
activity series can replace any element under it. Teacher tip: You can use the analogy
that ionic compounds have to be a “boy” and a “girl”. This is why a metal replaces a
metal or a nonmetal replaces a nonmetal.
Examples:
Zn + CuCl2 Æ Cu + ZnCl2
zinc replaces Cu because Zn is higher on the activity series
F2 + 2 NaCl Æ 2 NaF + Cl2
fluorine replaces Cl because F is higher than Cl
Cu + LiF Æ no reaction because Cu is lower than Li on the activity series
6
Terms and Concepts:
Binary compound
Ionic compound
Molecular compound
Polyatomic ions
Naming compounds
Writing chemical formulas
Reactants
Products
Yields
Single replacement
Oxidation numbers
Double replacement
Endothermic
Exothermic
Activity series
Chemical reactions
Word equations
Law of conservation of
matter
Instructional Resources
www.pogil.org Inquiry based activities - You will need to sign up for a password.
Go to the curriculum materials tab, select downloadable activities, go to bottom of page
and click on selected activities
www.ChemistryInquiry.com Inquiry based activities, sample ones can be printed or
entire collection can be ordered.
www.Flinnsci.com - Great source for MSDS sheets and safety information, along with
links to other teacher resources.
7
Nomenclature and Chemical Reactions
Activity #1 – Balancing Equations with Manipulatives.
Questions to be investigated
How do I balance equations?
Objectives
The student will be able to balance equations using coefficients and following the
law of conservation of matter.
Teacher Notes
The teacher will need to print copies of the “cards” to have enough for each
group of students (extra hint – laminate the cards). Groups of 2 are
recommended.
Materials
Worksheet for each student and a set of cards for each student.
Sources
www.middleschoolscience.com
Procedure/Description of Lesson
Students will use cards with symbols of elements and compounds and
coefficients to learn how to balance equations and apply the law of conservation
of matter. The cards can be made by hand as explained below or cards can be
printed on a color printer from the website. Student and teacher handouts are
following.
8
Balancing Chemical Equations Activity
by Liz LaRosa
www.middleschoolscience.com
Objectives:
•
•
•
•
•
•
to
to
to
to
to
to
read chemical equations
identify elements by their chemical symbol
count atoms
identify the coefficients and subscripts in a chemical equation.
label the reactants and products of a chemical equation
balance chemical equations
Materials: These account for one complete set. Color scheme is VERY important
for visualization during the activity.
on 3x5 Index
1 red
2 orange 6's
Cards
"Reactants"
CO2
Fe
N2 Na2SO4
4 red 2's
2 black 7's
on 5x8 Index
Cards
CH4
4 blue 3's
2 blue "+"
Al
C2H6
H2
4 green 4's
1 black
"yield" sign
--->
Al2O3
CaCl2
H2O NaCl P4O10
2 purple 5's
1 purple
"Products"
C
Fe3O4 NH3
Na
O2
P4
CaSO4 H2O2 Na2O
9
Pre Lab Questions:
Answer the following before you begin the activity:
5H2
1. What number represents the Coefficient?
_____
2. What number represents the Subscript?
_____
3. What element is represented by the letter "H"?
_____
4. How many "H's" do you have? _____
Procedure:
1. Using your set of index cards, replicate the chemical equation onto your desk.
2. Label the reactant side and the product side.
Record the following information into Table 1:
3.
4.
5.
6.
7.
8.
Identify the elements on the reactant side.
Count the number of atoms for each element.
Identify the elements on the product side.
Count the number of atoms on the product side.
Are the 2 sides equal? If not, the equation is not balanced.
The index cards numbered 2 - 7 are your coefficients. They can ONLY be
placed in front of the elements. You can not change the subscripts.
9. Choose an element that is not balanced and begin to balance the equations.
10. Continue until you have worked through all the elements.
11. Once they are balance, count the final number of Reactants and Products.
12. Write the balanced equation.
13. Can your equation be simplified?
10
Data:
Table 1: Chemical Equations (whole page, large boxes, sideways into lab book)
Make the following
Reactants Products Balanced
Equations on your Reactants Products
- Final
- Final
Equation
desk
H2 + O2 --> H2O
H2O2 --> H20 + O2
Na + O2 --> Na2O
N2 + H2 --> NH3
P4 + O2 --> P4O10
Fe + H2O --> Fe3O4
+ H2
C + H2 --> CH4
Na2SO4 + CaCl2 -->
CaSO4 + NaCl
C2H6 + O2 --> CO2 +
H2 O
Al2O3 --> Al + O2
Analysis/Results:
1.
2.
3.
4.
5.
What does "-->" mean?
What side of the equation are the reactants found? products?
Why must all chemical equations be balanced?
Why can't the subscripts be changed?
What does it mean to "simplify" the equation?
Conclusion:
2-3 sentences on what you learned.
11
TEACHER NOTES:
The index cards are a bit time consuming to create. I had some students help at lunch
time for a few days. Once done, you can laminate them and have them forever! The
materials account for one complete set which is good for 2-3 students to use.
Print activity cards on card stock instead of making index cards for quicker set up.
The color coding is very important for visualization. It is easier and quicker to locate
the elements that you are trying to balance. If everything is in black ink, it’s harder to
distinguish the equation contents.
© Copyright 2000, E. S. Belasic
12
Balancing Equations Lab: TEACHER ANSWER KEY
Table 1: Chemical Equations
Make the following
Reactants
Equations on your desk
Products
2
hydrogen
2
hydrogen
4
hydrogen
1 oxygen
2
2 hydrogen
hydrogen
2 oxygen
4
hydrogen
H2 + O2 --> H2O
2 oxygen
H2O2 --> H20 + O2
2 oxygen
Reactants - Products
Final
- Final
1 sodium
3 oxygen
2 sodium
4 oxygen
4 sodium
2 oxygen
1 oxygen
2 oxygen
2 nitrogen
Na + O2 --> Na2O
2 nitrogen 1 nitrogen
N2 + H2 --> NH3
P4 + O2 --> P4O10
2 oxygen
1 iron
Fe + H2O --> Fe3O4 +
H2
2 hydrogen
1 oxygen
1 carbon
C + H2 --> CH4
2 hydrogen
2sodium
Na2SO4 + CaCl2 -->
CaSO4 + NaCl
same as
2 H2 + O2 -->
final
2 H2O
reactants
same as
final
reactants
2 H2O2 -->
2 H20 + O2
same as
4Na + O2 -->
final
2 Na2O
reactants
same as
N2 + 3H2 -->
final
2 NH3
reactants
6
hydrogen
4
4
same as
phosphorus phosphorus
P4 + 5O2 -->
final
P4O10
reactants
10 oxygen 10 oxygen
3 iron
3 iron
same as 3Fe + 4H2O 2
-> Fe3O4 +
8 hydrogen final
hydrogen
4H2
reactants
4 oxygen
4 oxygen
1 carbon
1 carbon
same as
C + 2 H2 -->
final
CH4
4
reactants
4 hydrogen
hydrogen
1 sodium 2 sodium
2 hydrogen 3 hydrogen
4
phosphorus
Balanced
Equation
1 sulfur
1 sulfur
1 sulfur
4 oxygen
4 oxygen
4 oxygen
1 calcium
1 calcium
1 calcium
same as
final
reactants
Na2SO4 +
CaCl2 -->
CaSO4 +
2 NaCl
13
C2H6 + O2 --> CO2 +
H2O
2 chlorine
1 chlorine
2 carbon
1 carbon
6 hydrogen 2 hydrogen
2 oxygen
Al2O3 --> Al + O2
2 chlorine
4 carbon
12
hydrogen
3 oxygen
14 oxygen
2
1
4
aluminum aluminum aluminum
3 oxygen
same as 2 C2H6 + 7O2
final
--> 4CO2 +
reactants
6H2O
2 oxygen
6 oxygen
same as
final
reactants
2 Al2O3 -->
4Al + 3O2
Assessment Ideas
Give students a quiz on the parts of an equation and a quiz on balancing
equations before moving on. Summative assessment would be balancing
equations and answering questions on a unit test.
14
Nomenclature and Chemical Reactions
Activity #2 – Creating Ionic Compounds
Questions to be investigated
How do I name ionic compounds and write correct chemical formulas?
Objectives
The student will be able to name ionic compounds and write correct chemical
formulas by building compounds from cards.
Teacher Notes
Teacher will need to make a set of cards for each group of students. Laminating
and storing cards in Ziploc bags is suggested.
Materials
Worksheet per student and one set of cards per group of 2 students.
Real-World Connections
By knowing how to read, name and write chemical compounds, students will be
able to read labels on food item, cleaning products, health and beauty products,
etc.
Sources
ESC Region XIII
http://www.5.esc13.net/science/docs/ion%20ionic%20manipulatives.pdf
http://www.esc13.net/science/docs/creating%20ionic%20compounds.pdf
Procedure/Description of Lesson
Students will use cards to building molecules and from that determine the correct
chemical formula, then name the compound. See next page for student
handout.
15
16
17
18
19
20
Assessment Ideas
Lab Activity – Ionic Compounds and Nomenclature
Teacher sets up clear vials with tops with a few grams of solid. The vial is
labeled EITHER with the name OR the formula. The students are to determine
the missing piece. Teachers can set up as many or as few sets as they wish and
choose which ever compounds they have available. Suggestion: use a variety of
colored compounds and compounds with different crystal size. If you are
worried about students opening the vials, then place 2 or 3 in a Ziploc bag.
See attached worksheet.
Game – Salty Eights
A card game by Key Curriculum Press (www.keypress.com) from their Living by
Chemistry program, Unit 1: Alchemy. The idea behind the game is for students
to make compounds from the cards which have a variety of elements with their
valence states. Points are awarded based on the complexity of the molecule.
21
Ionic Compounds and Nomenclature
Activity
Name_____________
Date______Hour____
There are 5 sets of vials. Each vial contains a different ionic compound. The vial either
has the name, or the formula, but not both.
You need to complete the data chart. You may use a periodic table.
Name
Set #1
Formula
Color
Description
Set #2
Set #3
Set #4
Set #5
22
Nomenclature and Chemical Reactions
Activity #3 – Chemical Reaction Equations
Questions to be investigated
How do I balance equations and use the coefficients to do mole ratios?
Objectives
The student will learn how to balance equations and draw reactions and then
apply the coefficients to mole ratios.
Teacher Notes
Teacher may want to have magnets or bingo chips of different colors/shapes to
use on the board to show balancing and rearranging of atoms and to help
modeling the drawing of reactions.
Materials
Worksheets
Real World Connections
Can discuss how industrial processes and the manufacture of pharmaceuticals
rely on ratios and balanced equations to acquire the desired amounts.
Sources
www.pogil.org
Go to curriculum materials and click on downloadable items, then go towards
bottom of page and click on collected activities, you will need to sign up for a
password, activities are useable for one year from time of download
Procedure/Description of Lesson
Students will write their own definitions, analyze a balanced equation and draw a
diagram of it, then use the mole ratios to solve mole-mole or mole-mass problems.
Student handout is on next page.
23
24
25
26
27
Assessment Ideas
Give students a set of blocks or colored bingo chips and ask them to a balance
an equation by diagram. Then using simple numbers for mental math have them
do mole-mole and mass-mass problems (formative).
Give students a worksheet with practice problems (formative).
Variety of test questions, multiple choice and working out (summative).
28
Nomenclature and Chemical Reactions
Activity #4 – Chemical Reactions Lab
Questions to be investigated
How do I predict the products of a reaction?
Objectives
The student will observe and perform several chemical reactions. They will be
able to predict the products, balance the equations, and in some cases decide if
the reaction was endothermic or exothermic. C3.4A, C3.4B, C5.2A, C5.6b
Teacher Notes
The reactions in this lab could be done via demonstration if lab facilities or
quantity of materials are an issue. If done via demonstration then students
should write down what the instructor is doing and some observations. If no
fume hood is available, omit station 7.
Materials
Magnesium ribbon
Bunsen burner
Silver nitrate solution (0.1M)
Sodium chloride solution (0.1M)
Zinc metal
Hydrochloric acid (1.0 M)
Copper (II) sulfate solution (0.1M)
Barium chloride solution (0.1M)
Sodium sulfate solution (0.1M)
Hydrogen peroxide (3%)
Manganese (IV) oxide
Sulfur
Copper (II) sulfate hydrate
Matches
Alcohol burner with ethanol or methanol
29
Safety Concerns
Students must wear goggles and aprons at all times.
Station 1: DO NOT look directly at the burning magnesium – it can damage your
eyes
Station 2: Silver nitrate can stain skin and clothing.
Station 3: Hydrochloric acid is corrosive to skin, use caution. Have baking soda
available to neutralize spills.
Station 4: Copper (II) sulfate is a skin irritant.
Station 5: None, but see disposal note.
Station 6: Don’t get hydrogen peroxide in cuts.
Station 7: MUST BE DONE IN FUME HOOD.
Station 8: Copper (II) sulfate hydrate can be a skin irritant. Do not breathe
fumes while heating.
Station 9: Alcohol burners do get warm. Methanol is very hot and burns nearly
invisible. Ethanol burns with a blue flame and is safer.
Disposal: Dispose of all substances per MSDS sheet or disposal methods in the
Flinn Scientific Chemical Catalog. MSDS sheets and safety information can be
found at www.FlinnSci.com .
Real-World Connections
Can relate reactions to the fact that many items (foods, pharmaceuticals) are
made through chemical reactions. Discuss that your body works because of
many chemical processes and reactions.
Sources
http://staff.imsa.edu/science/chemistry/web/Chemical%20Reactions%20Labrevised.pdf
Procedure/Description of Lesson
Students will perform a series of chemical reactions, make observations, and
balance the equations they performed. Students will identify types of reactions,
parts of an equation, and give evidence of a chemical reaction.
See Lab Handout below:
30
Chemical Reactions Lab
Purpose: to become more familiar with different types of chemical reactions by
conducting several reactions, noting the results, and discussing observations with
colleagues.
Procedure: At each of the nine stations, there are directions for you to followincluding directions for waste disposal – FOLLOW ALL DIRECTIONS
CAREFULLY!
You should visit only six of the nine stations. You MUST visit stations 6, 8 and 9.
You will then choose one station from stations 1 and 7, one station from stations 2 and
5 and one station from stations 3 and 4. You do not need to move through the stations
in any particular order. You MUST wear your safety goggles at ALL TIMES!
At each station, answer the following questions in your lab notebook or on your
paper:
a. How did you know a chemical reaction took place?
b. Formula of reactant(s)
c. Formula of product(s)
d. Type of chemical reaction
e. Write the balanced equation for the reaction (including all physical states).
Station 1:
1. Get a strip of magnesium ribbon (about 2.5 cm long). Holding it with forceps,
ignite the ribbon in a Bunsen burner flame. Do not look directly at the
burning magnesium! Looking directly at the burning magnesium could
damage your eyes.
2. Hold the burning ribbon over a glass plate so that no burning magnesium lands
on the lab bench.
Word equation: Magnesium reacts with oxygen to produce magnesium oxide.
Station 2:
1. Place 10 drops of silver nitrate into a small test tube. Add 10 drops of sodium
chloride to the same test tube.
Word equation: Aqueous silver nitrate reacts with aqueous sodium chloride to produce
solid silver chloride and aqueous sodium nitrate.
31
Station 3:
1. Place a small piece of zinc into a small test tube. Add enough dilute hydrochloric
acid (HCl) to just cover the piece of zinc.
Word Equation: Zinc reacts with aqueous hydrochloric acid to produce aqueous zinc (II)
chloride and hydrogen gas.
Station 4:
1. Place a small piece of magnesium ribbon (about 10 mm long) into a small test
tube.
2. Add enough copper (II) sulfate to just cover the ribbon. Set aside for 15
minutes. Examine the contents of the test tube. If no change is observed, notify
your teacher.
Word equation: Aqueous Copper (II) sulfate reacts with magnesium to produce
aqueous magnesium sulfate and copper.
Station 5:
1. Place 10 drops of barium chloride into a small test tube. Add 10 drops of sodium
sulfate to the same test tube.
Word equation: Aqueous barium chloride reacts with aqueous sodium sulfate to make
barium sulfate and aqueous sodium chloride.
Station 6:
1. Place 20 drops of hydrogen peroxide into a small test tube.
2. Add a small amount of manganese (IV) oxide to the tube (just enough to cover
the bottom of the test tube). HINT: manganese (IV) oxide is a catalyst. It is not
a reactant or product, but it speeds up the rate of the reaction. A catalyst is
indicated in a chemical reaction by writing the formula of the catalyst over the
arrow.
Word equation: Aqueous hydrogen peroxide produces water and oxygen.
Station 7: USE THE FUME HOOD FOR THIS PROCEDURE!!
1. Place a small amount of sulfur into a deflagration spoon. Heat over a Bunsen
burner until the sulfur begins to burn.
Word equation: Sulfur reacts with oxygen to yield sulfur dioxide gas.
32
Station 8:
1. Place a small amount (a small scoop) of hydrated copper (II) sulfate into a small
test tube. Heat the hydrate over a Bunsen burner until the chemical reaction is
complete (the reaction should be obvious). NOTE: A hydrate is a compound that
contains water. The formula of a hydrate is written a little differently than
formulas for other compounds. The formula for the hydrate of copper (II) sulfate
is written CuSO4. 5H2O. This means there are five water molecules bound to one
CuSO4 molecule. (The correct name for this compound is copper (II) sulfate
pentahydrate).
Word equation: When copper (II) sulfate pentahydrate is heated, anhydrous copper (II)
sulfate and water vapor are produced. (Anhydrous means “no water”)
Station 9:
1. Use the matches/lighter to ignite the methanol in the lamp by lighting the wick.
2. Extinguish the flame by putting the cap over the wick.
Word equation: Methanol reacts with oxygen to produce carbon dioxide gas and water.
Questions to answer in your lab notebook or on paper for the next class:
1. Name five types of chemical reactions.
2. What is a reactant in a chemical reaction?
3. What is a product in a chemical reaction?
4. Name four ways you can tell a chemical reaction has taken place.
5. What does the symbol Æ mean in a chemical equation?
6. Give the four symbols for physical states of reactants and products, and tell what
each means.
7. Why must chemical equations be balanced?
Conclusion: Was the purpose of this lab achieved? What evidence do you have to
support your answer?
Revised January 11, 2008
http://staff.imsa.edu/science/chemistry/web/Chemical%20Reactions%20Labrevised.pdf
Assessment Ideas
Give students a worksheet with equations. Have the students predict the
products, balance the equations, and identify the type of reaction (formative).
Do the same for a unit test (summative).
33
Nomenclature and Chemical Reactions
Activity #5 – Metal/Metal Ions Lab Simulation
Questions to be investigated
How do I predict products of a single replacement reaction? What is an activity
series? How do I draw representations of reactions?
Objectives
The student will perform an online lab simulation of single replacement reactions
to create an activity series. Then the student will predict which reactions occur
and what the products are. Lastly, they will draw diagrams to represent the
reactions.
Teacher Notes
This is an online simulation. There is an accompanying worksheet to print for
the students to fill while they do the simulation.
Materials
Worksheet packet for each student.
Real-World Connections
Discuss electroplating and reactivity of metals. A lot of jewelry is made of silver,
gold, or copper because these metals are very unreactive.
Sources
www.chem.iastate.edu/group/Greenbowe/sections/projectfolder/animationsindex
.htm
Procedure/Description of Lesson
Students will complete an online lab simulation from the above site. After
clicking the link, select Reactions of Metals and Metal Ions Simulation. The
handout can be printed from the item below the simulation which is labeled as a
tutorial.
Assessment Ideas
Give students an activity series to use and have them predict if a reaction will
occur and if so, what the products would be (formative).
Give the students a scenario related to extracting metals or reactivity and ask
them to explain what happened based on the activity of metals and single
replacement reactions (summative).
Have students perform “wet” lab doing four single replacement reactions.
Students will predict products, balance equations, and create an activity series
for the four metals used and hydrogen. See handout below. Wear goggles, use
caution with acid, metals may NOT go down the drain.
34
Single Replacement Reactions
Background Information:
In nature, elements can occur either free, meaning uncombined with other elements, or
chemically combined in a compound. The tendency of a particular element to combine
with other substances is a measure of the activity of that element. The more active an
element is, the more likely it is to combine. In a single replacement reaction, an
uncombined element replaces a less active element that is combined in a chemical
compound. The less active element is then freed from the compound.
For example, in the reaction
Zinc +
copper sulfate Æ
zinc sulfate + copper
Zinc replaces the less active copper, combines with sulfate, and frees the copper from
the compound.
In this investigation, you will observe how various metals undergo single replacement
reactions when placed in acid. If the metal is more active than the hydrogen in the acid,
it will replace the hydrogen and hydrogen will be released as a gas.
Problem: How does a single replacement reaction occur?
Materials: (per group)
Safety goggles,
1M hydrochloric acid
Graduated cylinder
Copper (cut wire in to pieces of 1-cm length)
Iron (nail)
5 test tubes
test-tube rack
Zinc
Aluminum
Magnesium (cut into 1-cm lengths)
Procedure:
1. Label your test tubes with the names of the metals listed in the materials.
2. Put on your safety goggles. Carefully pour approximately 5 mL of HCl into each
test tube. (Make sure the amount of HCl is the same in each test tube.
3. One at a time, place the appropriate metal in each test tube. Record your
observations for each metal. Feel each test tube as the reaction proceeds and
record your observations.
4. When you have completed the investigation, carefully pour off the acid, rinse the
metal several times with water, and put it into a container provided by your
teacher. Do not put any unused metal in the sink.
35
Observations:
1. What did you observe in the test tube with the acid and
a.
b.
c.
d.
e.
magnesium_______________________________________________________
aluminum________________________________________________________
iron_____________________________________________________________
copper___________________________________________________________
zinc_____________________________________________________________
Conclusions:
1. Write and balance the single replacement reaction that has occurred between the
acid and each metal.
a. magnesium
b. aluminum
c. iron
d. copper
e. zinc
2. Were these reactions endothermic or exothermic? _______________________
Explain__________________________________________________________
________________________________________________________________
36
Critical Thinking and Application
1. Which of the metals are more active than hydrogen? _________________
2. Which of the metals are less active than hydrogen? _____________________
3. What could you do to prove that hydrogen gas was produced as a result of these
reactions? ________________________________________________________
______________________________________________________________
4. The rate at which hydrogen gas is produced is a result of these single
replacement reactions is an indication of the relative activity of the metals. List
the order of their activity from most active to least active.
________________________________________________________________
______________________________________________________________
5. Nonmetals can also be involved in single replacement reactions. If chlorine is
more active than bromine, write the equation for the reaction between chlorine
and potassium bromide.
________________________________________________________________
________________________________________________________________
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Nomenclature and Chemical Reactions
Activity #6 – ChemQuest
Questions to be investigated
How to balance equations, identify types of reactions, and predict products of a
reaction.
Objectives
The student will be able to label the parts of an equation, balance equations,
predict the products of reactions, and identify the type of reactions.
Materials
Worksheet packet for each student.
Sources
www.ChemistryInquiry.com
These Chemquests are being used with permission of Jason Neil. The entire set
of Chemquests, answer keys, and skill practice worksheets are on a CD-rom that
can be purchased from the website.
Procedure/Description of Lesson
Chemquests are designed to be an inquiry learning cooperative group activity.
Instead of lecturing on the topic, the instructor gives a short introduction to the
topic, and then places the students in groups of 2-3. The students then work
through the Chemquest to discover and figure out the concept. Go over
answers/discuss when students are done, then re-teach if necessary.
See student handouts below.
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Assessment Ideas
Give a formative quiz the next day on labeling the parts of an equation and just
balancing. Predicting products and more complicated balancing can be on a
summative unit test.
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