Download Chemical Reactions

Aqueous Chemical Reactions
In this experiment, you will observe (on video and in lab) examples of three basic types of chemical
reactions that occur in water which are described below. You will write your observations of the
reactions. Based on those observations and the given word equations, you will write complete,
balanced chemical equations to effectively communicate the chemistry of the reactions.
1. Single Replacement: A + BC  AC + B
In this type of reaction, a more “active metal” displaces another element in solution. These reactions
can be further classified as a solid metal reacting with a) a metal ion solution, b) an acid solution, or c)
water. An example of each is provided below:
a) When a solid metal reacts with a metal solution, the solid metal’s ions go into solution
while the metal ions originally in solution plate out onto the surface of solid metal
e.g., Zn (s) + CuSO4 (aq)  ZnSO4 (aq) + Cu (s).
b) When a solid metal reacts with an acid, the metal replaces hydrogen in the acid to produce
hydrogen gas while the metal ion goes into solution with the anion from the acid
e.g., Mg (s) + 2HCl (aq)  H2 (g) + MgCl2 (aq).
c) When a solid metal reacts with water, the metal replaces hydrogen in the water to produce
hydrogen gas while the metal ion goes into solution with hydroxide ion
e.g., Ca (s) + 2 H2O (aq)  H2 (g) + Ca(OH)2 (aq).
To predict whether or not a single-replacement reaction will occur, we refer to the Activity Series for
Metals (shown on the next page).
Activity Series for Metals
Li > K > Ba > Sr > Ca > Na > Mg > Al > Mn > Zn > Fe >
Cd > Co > Ni > Sn > Pb > (H) > Cu > Ag > Hg > Au
If a solid metal is “more active” – i.e., higher on the Activity Series – than the metal ion in solution or
hydrogen for acids, the more active metal will displace the less active ion, so a reaction occurs. The
more active metal goes into solution while the less active ion either plates out for a metal ion or
bubbles out as a gas for hydrogen ion. If the solid metal is less active than the metal ion or hydrogen
in the compound, then no reaction occurs. Only six metals (Li, K, Ba, Sr, Ca, and Na) – called “active
metals” – react directly with water to produce hydrogen gas and a metal hydroxide solution. These
active metals are the first six metals in the Activity Series.
2. Double Replacement/Precipitation: AB + CD  AD + CB
These reactions involve the mixing of two aqueous ionic compounds to produce a precipitate, an
insoluble ionic compound. The products of a double-replacement/
precipitation reaction can be predicted by switching the cations of the two compounds and using the
Solubility Rules (see below) to determine if the compounds produced are soluble or insoluble.
GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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Solubility Rules for Ionic Compounds in Water
The compound is SOLUBLE if it has:
The compound is INSOLUBLE if it has:
1. Group IA ions and ammonium ions
5. Carbonate, chromate, and phosphate ions, except
compounds with Group IA and ammonium salts of
these ions are soluble
2. Acetate, nitrate, chlorate, and perchlorate ions
3. Chloride, bromide, or iodide ions except
compounds with Ag+, Pb+2, Hg2+, and Hg2+2 are
insoluble
4. Sulfate ions- except compounds with Ag+, Ca2+,
Sr2+, Ba2+, Pb2+, and Hg22+ salts of sulfate are
insoluble
6. Sulfide ions, except Group IA, ammonium, Ca+2,
Sr+2, and Ba+2 salts of sulfide ions are soluble
7. Hydroxide ion, except Group IA, ammonium,
Ca+2, Sr+2, and Ba+2 salts of sulfide ions are soluble
Soluble ionic compounds will dissolve in water, so their physical states are indicated as aqueous, (aq),
while insoluble ionic compounds will not dissolve in water, so their physical states are indicated as
solid, (s). For a precipitation reaction to occur, at least one of the products must be insoluble; if both
products are soluble, then no reaction occurs. The presence of a precipitate is observed in the lab as a
cloudy mixture that results when two solutions are mixed. The following is an example of a doublereplacement/precipitation reaction: Pb(NO3) 2 (aq) + K2CrO4 (aq)  2KNO3 (aq) + PbCrO4 (s)
3. Double Replacement/Acid-Base Neutralization: HX (aq) + YOH (aq)  H2O (l) + HX (aq)
These reactions occur between an acid and a base. In general, acids are compounds that produce
hydrogen ions (H+), also called protons, when dissolved in water. The chemical formulas for acids are
most often given with the H’s at the beginning, so acids are usually easy to recognize. A few common
acids are hydrochloric acid, HCl(aq), nitric acid, HNO3(aq), and sulfuric acid, H2SO4(aq). Bases are
compounds that produce hydroxide ions (OH–) when dissolved in water. A few common bases are
sodium hydroxide, NaOH, potassium hydroxide, KOH, calcium hydroxide, Ca(OH)2, and barium
hydroxide, Ba(OH)2. Other types of bases contain carbonate ion, CO3–2, and hydrogen carbonate (or
bicarbonate) ion, HCO3–.
The two types of acid-base neutralization reactions involve a) an acid reacting with a base (containing
the hydroxide ion (OH–)) to produce water and a salt (an ionic compound) or b) an acid reacting with a
base containing carbonate (CO3–2) or hydrogen carbonate ion (HCO3–) to produce water, carbon
dioxide gas, and a salt. An example of each is provided below:
a) When an acid reacts with a base containing hydroxide ion (OH–) to produce water and a
salt, the hydrogens from the acid combine with the hydroxide from the base to form water while
the salt is formed by combining the cation from the base with the anion from the acid. The
following is an example of this type of reaction: HCl (aq) + NaOH (aq)  H2O (l) + NaCl (aq).
b) When an acid reacts with a base containing carbonate (CO3–2) or hydrogen carbonate
ion (HCO3–) to produce water, carbon dioxide gas, and a salt, the hydrogens from the acid
combine with the carbonate or hydrogen carbonate from the base to form water and carbon
dioxide gas while the salt is formed by combining the cation from the base combining with the
anion from the acid—e.g., HCl (aq) + NaHCO3 (aq)  H2O (l) + CO2 (g) + NaCl (aq).
GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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**Lab Notebook**
Record observations for all of the chemical reactions carried out during the lab in your lab book.
These observations should include:
 observations of the reactant(s) before the reaction
 observations of the reaction mixture during the reaction
 observations of the product(s) after the reaction.
Your observations of a material should contain the color, clarity and state of matter, plus any
useful descriptions of the material (for example, a sample of magnesium might be described as a
smooth, shiny, silver, opaque solid).
Your observations of the reaction in progress should include anything of potential interest, such as
“the color changed from green to blue”, “a pungent odor is present now”, “the test tube is getting
warmer” or “bubbles are forming on the surface of the magnesium”.
Procedure:
Safety and waste disposal directions are listed with each procedure.
General Directions:
1. Carry out the reactions using the approximate quantities of reagents indicated. Unless otherwise
stated, use test tubes. To estimate 2 mL, measure 2 mL of water in a graduated cylinder and pour it
into a test tube. Save this test tube for comparison.
2. When combining solutions in a test tube, tap the tube a few times or use the Vortex mixer to ensure
that the solutions have mixed completely.
4. There are different concentrations of the HCl and NaOH used in this laboratory session. Check
labels carefully for the proper chemical and concentration!
A. Single-Replacement Reactions
CAUTION: AgNO3 will stain skin and clothes!
1. Place a piece of copper wire in a test tube with enough 1 M AgNO3 to cover it. Allow the test tube
to stand for 5-10 minutes. Note changes in the appearance of both the wire and the solution.
Dispose of the contents of the test tube in the waste jar in the hood.
Copper Metal
AgNO3 solution
Before reaction
During reaction
After reaction
GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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CAUTION: 3M HCl(aq) can damage skin and clothing on contact. Rinse any spills on skin
immediately with plenty of water for 10 minutes. Neutralize all spills on the lab bench with water or
NaHCO3 solution, and rinse your hands thoroughly.
2. Place a small piece of zinc metal in a test tube containing 2 mL of 3M HCl, and record your
observations. Dispose of the contents of the test tube in the waste jar in the hood.
Zinc Metal
HCl solution
Before reaction
During reaction
After reaction
3. Place a piece of zinc metal in a test tube with enough 1 M CuSO4 to cover it. Allow the test tube to
stand for 10 minutes. Note changes in the appearance of both the metal and the solution. Dispose
of the contents of the test tube in the waste jar in the hood.
Zinc Metal
CuSO4 solution
Before reaction
During reaction
After reaction
B. Double Replacement/Acid-Base Neutralization.
CAUTION! NaOH, HCl and H2SO4 can damage skin, eyes and clothing on contact. Rinse off
any spills immediately with plenty of water for 10 minutes. In the event of a spill in the
laboratory, notify your instructor immediately.
Acids and Bases – Identification:
Line up three small pieces of red litmus paper and 3 small pieces of blue litmus paper on a watch glass
leaving plenty of space between each. Place a drop of 0.1M HCl(aq) on one piece of red and one
piece of blue litmus paper using a stirring rod and record your observations. Then place a drop of
0.1M NaOH(aq) on a fresh piece of blue and red litmus paper and record your observations. Place a
drop of deionized water on the last fresh pieces of blue and red pieces of litmus paper and record your
observations.
GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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Example Observation Table:
Red litmus paper
Blue litmus paper
Before reaction
Reaction with 0.1M HCl
Reaction with 0.1M NaOH
Reaction with H2O
Acid-Base Neutralization Reactions:
1) Place 10 drops of 3M NaOH in a clean test tube. Add ten drops of 3M HNO3 to the same test tube
holding the NaOH. Feel the outside of the test tube and write down any observations.
Write the balanced equation for the reaction of NaOH with HNO3 in your lab notebook right below
your observations.
2) Place 10 drops of 3M NaOH in a clean test tube. Add 2 drops of phenolphthalein and stir with a
clean stir rod. Record your observations. Add 3M H2SO4 slowly drop wise to the NaOH in the test
tube. Count how many drops it takes to neutralize the NaOH. Record your results.
Observed color of NaOH Before
Adding Phenolphthalein
Observed color of NaOH After
Adding Phenolphthalein
Number of drops needed to
neutralize the NaOH
Write the balanced equation for the reaction of NaOH with H2SO4 in your lab notebook right below
your observations.
Dispose of all solutions in the waste container and rinse test tubes into the waste container in the hood.
C. Double Replacement/Precipitation Reactions
CAUTION: AgNO3 will stain skin and clothing! Pb containing compounds are toxic and should not
be ingested. HCl, HNO3 and NaOH are corrosive and can cause chemical burns and damage
clothing. Any hazardous chemical spilled on skin must be rinsed off with plenty of water for 1015 minutes. If any spills occur in the laboratory, notify your instructor immediately.
Use the 0.10 M solutions of each of these reagents (except Na2SO4 which is 1M, HNO3 which is 3M
and AgNO3 which is 1M). You will obtain solutions of AgNO3(aq), NaCl(aq), Ba(NO3)2(aq),
HNO3(aq) and Pb(NO3)2(aq). To EACH of them you will add solutions of NaNO3(aq), NaCl(aq),
Na2SO4(aq), NaOH(aq), KI(aq), and saturated Na2CO3(aq).
First, record observations of each solution before the solutions are mixed.
GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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You will mix the pairs of chemicals and observe the reactions between them, watching in particular for
the appearance of a precipitate. All observations should be recorded in your data table in your
notebook. If no change occurs, write “NR” for “No reaction”. If a precipitate appears or if the
solution changes in any other way, record your observations of the change.
AgNO3(aq)
NaCl(aq)
Ba(NO3)2(aq)
HNO3(aq)
Pb(NO3)2(aq)
NaNO3(aq)
NaCl(aq)
Na2SO4(aq)
NaOH(aq)
KI(aq)
Na2CO3
Here is an example data table. Your data table will be much larger so you can write in all of your
observations (consider using the “landscape” orientation of the notebook, because this table will be
wider than it is tall).
Procedure
NOTE: All waste for this part of the experiment should be poured into the labeled waste
containers in the hood and the test tubes rinsed with a minimum amount of water, which
should also be placed into the waste container. DO NOT dispose of any solutions or solids
down the drain.
1. Wash your well-plate thoroughly with soap and water, then rinse it completely with deionized
water. A dirty well-plate can give incorrect results.
2. Place 5 drops of each aqueous solution in the correct wells based on the table you constructed for
your observations.
3. For each of the following combinations, mix 10 drops of each solution in a clean test tube, so any
reactions that take place can be observed on a larger scale:



0.10 M Ba(NO3)2(aq) and 0.10 M NaOH(aq)
3 M HNO3(aq) and Saturated Na2CO3(aq)
0.10 M Pb(NO3)2(aq) and 0.10 M NaCl(aq)
4. Have your lab instructor sign off on your Double Replacement/Precipitation reaction observation table.
5. In the conclusion section of your laboratory notebook, write a balanced chemical equation and clearly
identify the solid product for any precipitation reactions that you observe.
GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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Your Lab Report Should include the following:




Header completed in your lab notebook.
A purpose statement (in notebook)
Brief outline of the procedures for each part (in notebook)
Each section of the experiment clearly labeled (eg: A. Single Replacement Reactions, B. AcidBase Neutralization Reactions, etc.)
 Observations clearly written under each section (in notebook)
 Data tables with a title, proper heading and units (in notebook)
 Results/Summary tables with a title, proper heading and units (in notebook)
 Conclusion (in notebook)
 Be sure to write out all of the balanced equations for the reactions that did form a
product in part C.
 Discussion Questions (answers written on pages 9-10)
GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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Name:_______________________
Section:___________________
Pre-Lab Questions – 5 Points
Write out ALL of the double replacement balanced equations for part C. Indicate which should form a
precipitate and which should not by circling either PPT or NO PPT. (Hint: look at the solubility rules)
1) PPT OR NO PPT ____NaNO3(aq) + ____AgNO3(aq)  _________________ + _________________
2) PPT OR NO PPT ____NaNO3(aq) + ____NaCl(aq)  _________________ + _________________
3) PPT OR NO PPT ____NaNO3(aq) + ____Ba(NO3)2(aq)  ________________+ _______________
4) PPT OR NO PPT ____NaNO3(aq) + ____HNO3(aq)  _________________ + _________________
5) PPT OR NO PPT ____NaNO3(aq) + ____ Pb(NO3)2 (aq)  ________________ + _______________
6) PPT OR NO PPT ____NaCl(aq) + ____AgNO3(aq)  _________________ + _________________
7) PPT OR NO PPT ____NaCl(aq) + ____NaCl(aq)  _________________ + _________________
8) PPT OR NO PPT ____NaCl(aq) + ____Ba(NO3)2(aq)  ________________+ _______________
9) PPT OR NO PPT ____NaCl(aq) + ____HNO3(aq)  _________________ + _________________
10) PPT OR NO PPT ____NaCl(aq) + ____Pb(NO3)2 (aq)  ________________ + _______________
11) PPT OR NO PPT ____Na2SO4(aq) + ____AgNO3(aq)  ________________ + ________________
12) PPT OR NO PPT ____Na2SO4 (aq) + ____NaCl(aq)  _________________ + _________________
13) PPT OR NO PPT ____Na2SO4 (aq) + ____Ba(NO3)2(aq)  ________________+ _______________
14) PPT OR NO PPT ____Na2SO4 (aq) + ____HNO3(aq)  _________________ + _________________
15) PPT OR NO PPT ____Na2SO4 (aq) + ____Pb(NO3)2 (aq)  ________________ + _______________
16) PPT OR NO PPT ____NaOH(aq) + ____AgNO3(aq)  _________________ + _________________
17) PPT OR NO PPT ____NaOH (aq) + ____NaCl(aq)  _________________ + _________________
18) PPT OR NO PPT ____NaOH (aq) + ____Ba(NO3)2(aq)  ________________+ _______________
19) PPT OR NO PPT ____NaOH (aq) + ____HNO3(aq)  _________________ + _________________
20) PPT OR NO PPT ____NaOH (aq) + ____Pb(NO3)2 (aq)  ________________ + _______________
21) PPT OR NO PPT ____KI(aq) + ____AgNO3(aq)  _________________ + _________________
22) PPT OR NO PPT ____KI (aq) + ____NaCl(aq)  _________________ + _________________
23) PPT OR NO PPT ____KI (aq) + ____Ba(NO3)2(aq)  ________________+ _______________
24) PPT OR NO PPT ____KI (aq) + ____HNO3(aq)  _________________ + _________________
25) PPT OR NO PPT ____KI (aq) + ____Pb(NO3)2 (aq)  ________________ + _______________
26) PPT OR NO PPT ____Na2CO3(aq) + ____AgNO3(aq)  ________________ + ________________
27) PPT OR NO PPT ____Na2CO3 (aq) + ____NaCl(aq)  _________________ + _________________
28) PPT OR NO PPT ____Na2CO3(aq) + ____Ba(NO3)2(aq)  ________________+ _______________
29) PPT OR NO PPT ____Na2CO3 (aq) + ____HNO3(aq)  _________________ + _________________
30) PPT OR NO PPT ____Na2CO3 (aq) + ____Pb(NO3)2 (aq)  ________________ + _______________
GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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Name:_______________________
Section:___________________
Discussion Questions – 33 Points Total
Write your answers on these pages and attach them to your report.
Translate each of the following word equations into a balanced chemical reactions by writing the
correct chemical formulas (including physical states) for the reactants and products. Make sure
to balance each equation.
Example: Aluminum metal reacts with oxygen.
aluminum metal +
4 Al (s)
+
oxygen gas
3 O2 (g)


2 Al2O3 (s)
A. Single-Replacement Reactions
1. (3 pts) Copper metal reacts with silver nitrate solution.
copper metal + silver nitrate

2. (3 pts) Zinc metal reacts with hydrochloric acid.
zinc metal + hydrochloric acid

3. (3 pts) Zinc metal reacts with copper(II) sulfate solution.
zinc metal + copper(II) sulfate 
B. Double Replacement/Precipitation) and Double Replacement/Acid-Base Neutralization
Reactions
Refer to your data table for the following selected sets of reactants and fill in the following blanks and
beaker drawings. An example NOT from this experiment is presented first.
Example: calcium acetate and ammonium sulfate
Reaction type: ____precipitation________
Molecular: Ca(CH3COO)2(aq) + (NH4)2SO4(aq)  CaSO4(s) + 2 NH4CH3COO(aq)________________________________
Ionic: Ca2+(aq) + 2 CH3COO-(aq) + 2 NH4+(aq) + SO42-(aq)  CaSO4(s) + 2 CH3COO-(aq) + 2 NH4+(aq)____________
Net Ionic: Ca2+(aq) + SO42-(aq)  CaSO4(s)______________________________________________________________

+

GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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1. lead(II) nitrate and potassium iodide
Reaction type: _______________(1 pt)
Molecular: ________________________________________________________________________(1 pt)
Ionic: ____________________________________________________________________________(1 pt)
Net Ionic: ________________________________________________________________________(1 pt)

+
(Beakers worth 1 point each)
2. nitric acid and sodium hydroxide
Reaction type: _______________(1 pt)
Molecular: ________________________________________________________________________(1 pt)
Ionic: ____________________________________________________________________________(1 pt)
Net Ionic: ________________________________________________________________________(1 pt)

+
(Beakers worth 1 point each)
Balancing and Categorizing Chemical Equations: (10 points)
Balance each of the 12 chemical equations given below, and identify each as one of the six types listed
below.
Single-Replacement reaction (SR)
Double-Replacement/Precipitation reaction (DR)
Acid-Base Neutralization reaction (N)
TYPE
_____ NiCl2 (aq)  _____ Ni (s) + _____ AlCl3 (aq)
_____ 1.
_____ Al (s) +
_____ 2.
_____ Ba(OH)2 (s) + ____ FeCl3 (aq)  ____ BaCl2 (aq) + ____ Fe(OH)3 (s)
_____ 3.
_____ H2SO4 (aq) + _____ Mg(OH)2 (s) _____ H2O (l) + _____ MgSO4 (aq)
_____ 4. _____ Na3PO4 (aq) + ____ MgCl2 (aq)  ____ Mg3(PO4)2 (s) + ___ NaCl (aq)
_____ 5. _____ H3PO4 (aq) + ____ NaOH (aq)  _____ H2O (l) + ____ Na3PO4 (aq)
GCC CHM 151LL: Aqueous Chemical Reactions
© GCC, 2017
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