Identify and balance 5 types of reactions

1
Unit Five Chemical Reactions

• Identify and balance 5 types of reactions
• Experimentally determine indicators of a reaction

2
Chemical Reactions

• Process by which the atoms of one or more
  substances are rearranged to form different
  substances
• Law of Conservation of Matter Matter is not
  created or destroyed during a chemical reaction.

3
Evidence of a Chemical Reaction

• Formation of a gas
• Bubbles
• Smell
• Formation of a solid (precipitate) from two
  aqueous solutions often solids are colorful
• Snow globe effect
• Paint look
• Jello consistency
• Change in temperature
• Test tube feels colder to you (endothermic
  reaction)
• Test tube feels warmer to you (exothermic
  reaction)

4
Writing Chemical Equations

• Read a description of the reaction
• Note what is reacted with what
• Note what is yielded or produced
• Write formulas for each compound
• Use to represent and
• Use ? to represent produces or yields
• Include states of matter where available
• (s) solid
• (l) liquid
• (g) gas
• (aq) dissolved in water

5
Balancing Chemical Equations

• Write the skeleton equation.
• BE SURE THE FORMULAS ARE WRITTEN CORRECTLY.
• Inventory reactants
• Inventory products
• Insert coefficients to make atoms of each element
  equal on both sides of the equation
• Reduce the coefficients if possible

6
Writing Balancing Equations Handout

1. Zn Pb(NO3)2 --gt Zn(NO3)2 Pb
2. AlBr3 Cl2 --gt AlCl3 Br2

7
Writing Balancing Equations

1. Zn Pb(NO3)2 --gt Zn(NO3)2 Pb
2. 2 AlBr3 3 Cl2 --gt 2 AlCl3 3 Br2
3. Na3PO4 CaCl2 --gt Ca3(PO4)2 NaCl

8
Writing Balancing Equations

• Zn Pb(NO3)2 --gt Zn(NO3)2 Pb
• 2 AlBr3 3 Cl2 --gt 2 AlCl3 3 Br2
• 2 Na3PO4 3 CaCl2 --gt Ca3(PO4)2 6 NaCl
• Complete 4, 5, 6, and 8 on your own.

9
iRespond Question
Multiple Choice
F
Potassium metal and chlorine gas combine to form
potassium chloride. Select the balanced
chemical equation.
A.) K1 Cl- --gt KCl
B.) K Cl --gt KCl
C.) K Cl2 --gt KCl
D.) 2K Cl2 --gt 2KCl
E.)
10
iRespond Question
Multiple Choice
F
Aluminum and hydrochloric acid react to form
aluminum chloride and hydrogen gas. Select the
balanced chemical equation.
A.) Al3 HClO3 --gt AlCl H
B.) Al 2HClO3 --gt AlCl3 H2
C.) Al HCl --gt AlCl3 H2
D.) 2Al 2HCl --gt 2AlCl3 3H2
E.) 2Al 6HCl --gt 2AlCl3 3H2
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iRespond Question
Multiple Choice
F
Calcium hydroxide and phosphoric acid react to
form calcium phosphate and water. Select the
balanced chemical equation.
A.) CaOH2 H3P --gt Ca3(PO4)2 H2O
B.) 3CaOH2 2H3PO4 --gt Ca3(PO4)2 6H2O
C.) 3Ca(OH)2 H32PO4 --gt Ca3(PO4)2 3H2O
D.) 3Ca(OH)2 2H3PO4 --gt Ca3(PO4)2 6H2O
E.)
12
Hydrogen gas and nitrogen monoxide react to form
water and nitrogen gas. Select the balanced
chemical equation.
iRespond Question
Multiple Choice
F
A.) 2H NO --gt H2O N
B.) 6H N2O3 --gt 3H2O 2N
C.) 2H2 2NO --gt 2H2O N2
D.) H2 2NO --gt H2O N2
E.)
13
Copper and sulfuric acid react to form copper
(II) sulfate and water and sulfur dioxide.
Difficult Equations to Balance
Cu 2 H2SO4 --gt CuSO4 2 H2O SO2
14
Writing Balancing Equations

1. Zn Pb(NO3)2 --gt Zn(NO3)2 Pb
2. 2 AlBr3 3 Cl2 --gt 2 AlCl3 3 Br2
3. 2 Na3PO4 3 CaCl2 --gt Ca3(PO4)2 6 NaCl
4. 2 K Cl2 --gt 2 KCl
5. 2 Al 6 HCl --gt 2 AlCl3 3 H2
6. 3 Ca(OH)2 2 H3PO4 --gt Ca3(PO4)2 6 H2O
7. Cu 2 H2SO4 --gt CuSO4 2 H2O SO2
8. 2 H2 2 NO --gt 2 H2O N2

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5 Types of Chemical Reactions

• Synthesis
• Combustion
• Decomposition
• Double-Replacement
• Single-Replacement

Five Types of Reactions Clip
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Synthesis Reactions

• A B --gt AB
• 2 or more compounds or elements go together to
  build a more complex compound

Synthesis Reaction Clip
Write the balanced chemical equation for the
reaction shown in the video clip. 2Al 3Br2 ?
2AlBr3
17
Combustion Reactions

• Oxygen combines with a substance and releases
  energy in the form of heat and light
• DIATOMIC OXYGEN IS ALWAYS A REACTANT!

Combustion Reaction Clip
In the video, the combustion reaction occurring
in the flask used up all of the oxygen gas in
flask. A vacuum formed as a result, and the egg
was drawn into the flask.
18
Decomposition Reactions

• A single compound breaks down into 2 or more
  elements or new compounds
• AB --gt A B

Decomposition Reaction Clip
In the video, hydrogen peroxide is decomposed to
form hydrogen gas and oxygen gas. Many bubbles
indicated this gas production. A catalyst of KI
was used to speed up the decomposition reaction.
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Double Replacement Reactions

• Exchange of ions between 2 ionic compounds
• AX BY ? AY BX
• Often produce a precipitate
• Solid, liquid, or gas product formed from two
  aqueous solutions
• Aqueous means dissolved in water.
• Example Cobalt (II) chloride reacts with sodium
  phosphate to produce cobalt (II) phosphate and
  sodium chloride.

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Single Replacement Reactions

• One element replaces another element in a
  compound
• A BX --gt AX B
• A metal will not always replace another metal.
  The reactivity of the metal is important to
  consider.
• Only a more active metal replaces a less active
  metal.
• A less active metal will not replace a more
  active metal. The reaction will simply not
  occur.
• Use the metal activity series to determine if
  single replacement reactions occur.

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Colored Pencil Corrections9-2 Practice Problems
(odd)

• NH3 HCl ? NH4Cl
• BaO H2O ? Ba(OH)2
• Zn Cu(NO3)2 ? Zn(NO3)2 Cu
• 7. Fe H2SO4 ? FeSO4 H2
• Co Cl2 ? CoCl2
• N2O5 H2O ? 2HNO3
• 13. C 2ZnO ? 2Zn CO2
• 15. PCl3 Cl2 ? PCl5
• CaH2 2H2O ? Ca(OH)2 2H2
• 19. C3H8 5O2 ? 3CO2 4H20

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As you come in,

• The Materials
• Remote control
• Periodic table
• Pick up an Intro to Chemical Reactions
  Investigations handout
• The Plan
• I-Respond Warm-Up Types of Reactions Practice
  Quiz
• Instructions for Intro to Chemical Reactions
  Investigations
• Collaborative investigations in the lab
• The Assessments
• TOMORROW Types of Chemical Equations Quiz
• Thursday Writing and Balancing Equations Quiz
• Friday Predicting Products and Balancing
  Equations Quiz

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iRespond Question
Multiple Choice
F
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1. When grilling burgers with your friends on
Saturday evening, your propane tank and gas grill
work together to perform the following
reaction C3H8 O2 ? CO2 H2O
A.) Synthesis
B.) Decomposition
C.) Combustion
D.) Single Replacement
E.) Double Replacement
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iRespond Question
Multiple Choice
F
DA07918A-FBE9-F94C-BCC6-31C7E98FCB39
2. If not stored properly, your hydrogen peroxide
can cause a mess in your medicine cabinet.
Hydrogen peroxide quickly breaks down in the
presence of light to produce oxygen gas and
hydrogen gas.
A.) Synthesis
B.) Decomposition
C.) Combustion
D.) Single Replacement
E.) Double Replacement
25
iRespond Question
Multiple Choice
F
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3. The white precipitate formed by acid rain on a
marble statue is produced in the following
reaction CaCO3(aq)H2SO4(aq)?CaSO4(s)H2CO3(aq)
A.) Synthesis
B.) Decomposition
C.) Combustion
D.) Single Replacement
E.) Double Replacement
26
9-2 Practice Problems (even)

• CaCO3 ? CaO CO2
• CH3CHO ? CH4 CO
• CaSO3 ? CaO SO2
• C2H6N2 ? C2H6 N2
• MnI2 ? Mn I2
• 2Mg TiCl4 ? 2MgCl2 Ti
• Br2 2NaI ? 2NaBr I2
• 2P 3Br2 ? 2PBr3
• H2SO4 2KOH ? K2SO4 2H2O
• 20. 2C6H6 15O2 ? 12CO2 6H2O

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Evidence of Chemical Reaction Writing Chemical
Equations Pre-Lab

• Youll visit three stations today.
• GOAL Follow instructions written on the lab
  carefully. Record your observations, and complete
  the questions about each station. Youll have 7
  minutes at each station to complete the
  observations and clean-up.
• GETTING STARTED Read the lab. Using the
  instructions, write an equation representing the
  reaction that should occur at each station. You
  have 5 minutes now to start individually.

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Starting Station One

• Station One Mg (s) HCl (aq) ?
• Single replacement reaction
• Magnesium is looking for a partner. Will Mg2
  like to bond with H or Cl-?
• What element will be left alone?
• Mg HCl ? MgCl2 H2
• Balance the equation.
• What do you think that the products will look
  like? In the lab, look for evidence of the
  reaction.

29
Starting Station Two

• Station Two KI (aq) Pb(NO3)2 (aq) ?
• Double replacement reaction
• KI Pb(NO3)2 ? KNO3 PbI2
• Balance the equation.
• What do you think that the products will look
  like? In the lab, look for evidence of the
  reaction.

30
Starting Station Three

• Station 3 NaHCO3(s) HC2H3O2 (aq) ?
• Double replacement reaction
• NaHCO3 HC2H3O2? NaC2H3O2 H2CO3
• Balance the equation.
• What do you think that the products will look
  like? In the lab, look for evidence of the
  reaction.
• NOTE The carbonic acid will decompose really
  quickly to produce some CO2. What do you think
  the CO2 will look like?

31
Predicting Products States of Matter

• 52. 2Al 6HCl ? 2AlCl3 3H2

32
Predicting Products States of Matter

• 52. 2Al(s) 6HCl(aq) ? 2AlCl3(aq) 3H2(g)
• 56.ZnCl2 (NH4)2S ? 2NH4Cl ZnS

33
Predicting Products States of Matter

• 56.ZnCl2 (aq) (NH4)2S(aq) ? 2NH4Cl(aq) ZnS(s)
• 59. HgSO4 2NH4NO3 ? Hg(NO3)2 (NH4)2SO4

34
Predicting Products States of Matter

• 59. HgSO4(aq) 2NH4NO3(aq) ? Hg(NO3)2(aq)
  (NH4)2SO4(aq)
• 60. Fe CuSO4 ? FeSO4 Cu

35
Predicting Products States of Matter

• 60. Fe (s) CuSO4 (aq) ? FeSO4 (aq) Cu (s)
• 67. Br2 2NaI ? 2NaBr I2

36
Predicting Products States of Matter

• 67. Br2 (l) 2NaI(aq) ? 2NaBr (aq) I2 (g)

37
Colored Pencil Corrections

• Al(NO3)3 NaOH Al(OH)3 NaNO3
• KClO3 KCl O2
• H3PO4 Mg(OH)2 Mg3(PO4)2 H2O
• NH4NO2 N2 H2O
• BaCl2 Na2SO4 NaCl BaSO4
• Fe2O3 CO Fe CO2
• Mg(OH)2 (NH4)3PO4 Mg3(PO4)2 NH3 H2O

38
Reactions in Aqueous Solution

• More than 70 of earth is covered by water
• 66 of the human body is water
• MANY chemical reactions occur in water
• Often form solids called precipitates
• Remember Ionic compounds dissociate in water.

39
Net Ionic Equations

• Represent reactions of ionic compounds in aqueous
  solution by writing complete ionic equations
• Remove spectator ions (those appear on both sides
  of the equation but arent in the precipitate)
• Leaves a net ionic equation that can be balanced

40
Chemical Reactions Pre-Lab

• Why do I set up the lab with so many aqueous
  solutions?
• Rate of Reaction
• Temperature warmer faster reaction particles
  are moving faster
• Concentration - of particles more particles
  faster reaction
• State of Matter dissolved means greater surface
  area more surface area faster reaction
• Surface Area - Filings, shot, powder, mossy,
  etc. greater surface area faster reaction
• Catalyst DOES NOT REACT lowers the activation
  energy of the reaction