Chemical Reactions

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Chemical Reactions
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Chemistry (2/25)

• Acid/Base Quiz
• Interpreting and Balancing chemical equations
• Due
• Acid/Base Nomenclature worksheet for partial
  credit

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Chemical Reactions Objectives

• 1.Classify and name compounds in chemical
  reactions
• 2.Describe chemical reactions in word and
  chemical equations.
• 3.Balance chemical equations based on the Law of
  Conservation of Mass.
• 4.Identify and classify types of chemical
  reactions and energy changes involved.
• 5.Predict products and energy changes in a
  chemical reaction.
• 6.Identify and test factors that affect the rate
  of chemical reactions.

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Chemistry (2/26)

• Infinite Campus Update
• Acid/Base Nomenclature Worksheet (10pts.)
• Acid/Base Quiz (15pts.)
• Check infinite a lot of missing assignments!
• Objectives
• Interpreting and Balancing chemical equations
• Homework
• Check for missing assignments on infinite campus
• Balancing chemical equations worksheet

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Chemical Reaction Pre-Test

• What is a chemical reaction?
• If matter is conserved during a chemical
  reaction, how is it new matter is created?
• 3. Complete the questions below on the following
  word equation
• Fe(s) O2 (g) ----gt FeO (s)
• Give an example of a reactant from this reaction.
• Give an example of a product from this reaction.
• Balance the chemical equation if needed.
• Circle the type of chemical reaction you think
  this represents.
• synthesis decomposition
  replacement
• neutralization combustion

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Chemical Reactions

• Substances chemically interact to form different
  substances.
• A substance can be an element or a compound.
• Chemical bonds are broken and created.
• Example Fe(s) O2 (g) ----gt FeO (s)

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Chemical Equations

• Fe O2 ------gt FeO
• Reactants
• Starting substances.
• Chemically interact with one another.
• Usually located to the left of the arrow.
• Products
• Ending substances.
• Substances formed from the chemical reaction.
• Usually located to the right of the arrow.

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Chemical Equations

• Fe(s) O2 (g) ------gt FeO (s)
• Abbreviations for state of matter in an equation.
• (s) substance in solid state
• (g) substance in gaseous state
• (l) substance in liquid state
• (aq) substance dissovled in water.
• (aqueous solution)

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Law of Conservation of Mass

• Fe(s) O2 (g) ------gt FeO (s)
• Are atoms destroyed or created during a chemical
  reaction?
• No, they are just rearranged to produce new
  substances.

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Law of Conservation of Mass

• Fe(s) O2 (g) ------gt FeO (s)

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Balancing Chemical Equations

• Why? Observe the Law of Conservation of Mass
• Rules
• 1. Add coefficients in front of substances, do
  NOT change subscripts.
• 2. First balance elements that only appear once
  on each side of the equation.
• 3. Make sure coefficients are expressed in lowest
  terms.

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Chemistry (2/27)

• Objectives
• Interpreting and Balancing chemical equations
• Review acid/base quiz
• Homework
• Balancing equations worksheet(due Thursday)
• Law of Conservation of Mass pre-lab qts. and
  hypothesis
• Review acids/bases nomenclature
• Check for missing assignments in infinite campus
• Lab
• Law of Conservation of Mass Lab (Thursday)

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Law of Conservation of Mass Lab

• Homework
• Read through the background and procedures
  section.
• Complete pre-lab questions and hypothesis.

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Balancing Chemical Equations

• a. K MgCl2 ---------gt KCl
  Mg
• b. Ag2O ---------gt Ag O2
• c. CH4 O2 -------gt CO2 H2O

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Chemical Equations
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Chemistry (2/28)

• Objectives
• Interpreting and Balancing Chemical Equations
• Validate the Law of Conservation of Mass with
  scientific evidence.
• Due Today
• Balancing chemical equations worksheet (turn in
  tray)
• Law of Conservation of Mass pre-lab qts. and
  hypothesis
• Homework
• Balancing Chemical Equations practice problems
  (Fri.)
• Check for missing assignments in infinite campus

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Balancing Chemical Equations

• Dihydrogen monoxide sodium (bicarbonate) ---gt
  carbon dioxide sodium hydroxide dihydrogen
  monoxide

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Law of Conservation of Mass Lab

• Purpose
• Validate the Law of Conservation of Mass
• Lab Reminders
• Follow ALL lab procedures carefully.
• Use the same balance for all measurements.

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Acid/Base Nomenclature Quiz
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Exit Slip Interpret and Balance Chemical
Equations

• Cl2 (g) KBr (aq) ----gt KCl (aq) Br2 (l)
• Balance the equation if needed
• CH4 (g) O2 (g) ? CO2(g) H2O(g)
• Balance the equation if needed.
• Identify the diatomic molecule in this reaction.

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Exit Slip Interpret and Balance Chemical
Equations

• Cl2 (g) KBr (aq) ----gt KCl (aq) Br2 (l)
• Which reactant is a molecule?
• What is the chemical name of the product that is
  an ionic compound?
• What does (aq) mean?
• Balance the equation if needed
• CH4 (g) O2 (g) ? CO2(g) H2O(g)
• Balance the equation if needed.
• Identify the diatomic molecule in this reaction.

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Balancing Chemical Equations

• Dihydrogen monoxide sodium (bicarbonate) ---gt
  carbon dioxide sodium hydroxide dihydrogen
  monoxide
• convert to chemical equation
• Balance equation if needed.

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Law of Conservation Of Mass

• Matter is not created or destroyed.
• Matter is just rearranged.
• (mass of reactants mass of products)
• That is why it is important to balance chemical
  equations.

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Law of Conservation of Mass Inquiry Lab

• Purpose To prove mass is conserved in chemical
  reactions.
• Materials and Procedures Groups will establish
• Record and analyze data
• Establish a conclusion

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Open vs. Closed System
http//www.chem.umass.edu/people/botch/Chem122S08/
Chapters/Ch6/InternalE.html
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pre-AP Chemistry (2/20)

• Objectives
• Clarify misconceptions with writing and
  balancing chemical equations.
• Validate the Law of Conservation of Mass
• (Design, perform, and analyze chemical
  reaction between Alka Seltzer and tap water).

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States of Matter Abbreviations

• Fe(s) O2 (g) ------gt FeO (s)
• Abbreviations for state of matter in an equation.
• (s) substance in solid state
• (g) substance in gaseous state
• (l) substance in liquid state
• (aq) substance dissovled in water.
• (aqueous solution)

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Chemical Equations

• magnesium chloride fluorine yields magnesium
  fluoride chlorine
• 2. iron sulfuric acid yield iron(II)sulfate
  sulfur dioxide dihydrogen monoxide

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Pre-AP Chemistry (2/21)

• Reminder
• Quiz tomorrow over writing and balancing chemical
  equations. (complete extra practice problems
  from paper or webpage)
• Objective
• Validate the Law of Conservation of Mass
• (Design, perform, and analyze chemical
  reaction between Alka Seltzer and tap water).

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Pre-AP Chemistry (2/22)

• Reminder
• Quiz today over writing and balancing chemical
  equations. (complete extra practice problems
  from paper or webpage)
• Objective
• Validate the Law of Conservation of Mass
• (Design, perform, and analyze chemical
  reaction between Alka Seltzer and tap water).

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Chemical Equations
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Chemical Equations

• magnesium chloride fluorine yields magnesium
  fluoride chlorine
• 2. iron sulfuric acid yield iron(II)sulfate
  sulfur dioxide dihydrogen monoxide

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Law of Conservation of Mass Inquiry Lab

• Purpose ,Background, Hypothesis completed
• Objectives
• List materials needed for each experiment.
• List procedures specific enough for someone else
  to repeat. (sign-off by Ms. Leeper)
• Perform experiments and record data.
• (record all qualitative and quantiative data)

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Open vs. Closed System
http//www.chem.umass.edu/people/botch/Chem122S08/
Chapters/Ch6/InternalE.html
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Chemical Reactions Bell Ringer

• 1. N2 (g) H2(g) --------gt
  NH3(g)
• What is the chemical name of one of the
  reactants?
• b. What is the chemical name of the product?
• c. What state of matter is all the substances in
  this reaction?
• d. Balance the chemical equation if needed.

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Balancing Chemical Equations
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Types of Chemical Reactions

• 1. Synthesis (A B ----gt AB)
• 2. Decomposition (AB------gt A B)
• 3. Single Replacement (A BC ---gt B AC)
• 4. Double Replacement (AB CD ---gt CB AD)
• 5. Combustion (CxHx O2 ----gt CO2
  H2O)
• 6. Neutralization (Acid Base--gt H2O Salt)
• Each letter represents a substance

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Chemical Reactions Objectives

• Identify and classify types of chemical
  reactions.
• 2. Identify energy changes involved with chemical
  reactions.
• 3. Predict products and energy changes in a
  chemical reaction.

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Synthesis (Combination) Reaction

• 2 or more substances chemically combine to form a
  single substance.
• A B ---gt AB energy
• Energy released into surroundings is more than
  energy absorbed by the system.
• ( Energy of surroundings gt Energy of system)

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Decomposition Reaction

• A compound breaks down into simpler substances.
• AB energy ----gt A B
• Energy of system gt Energy of surroundings
• Why?

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Single Replacement Reaction

• An element replaces another element in a
  compound.
• A BC --------gt B AC energy
• Energy of surroundings gt Energy of system

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Double Replacement Reaction

• Exchange of cations between two compounds.
• AB CD energy ----gt CB AD more
  energy
• Energy of Surrounding gt Energy of System

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Combustion Reaction

• Fuel (hydrocarbons) reacts with oxygen to produce
  predictable substances and energy.
• CxHx O2 ----gt CO2 H2O ENERGY
• Energy of Surroundings gt Energy of System

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Neutralization

• Acid and Base react to produce predictable
  products.
• Changes the pH to 7 (neutral).
• Acid Base -------gt H2O Salt
• Salt An ionic compound.
• The cation comes from the base and the anion
  from the acid.

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Class Reminders

• Acid Rain Article (15pts.)
• Balance Chemical Equations Worksheet (10pts.)
• (balance and classify equations)
• Word Equation Worksheet (10pts.)
• 3rd Quarter Ends March 8th

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Chemical Reaction Lab

• Purpose
• Perform and observe types of chemical reactions.
• Determine reactants and predict products.
• Classify chemical reactions.
• Balance chemical reactions.
• Write a formal lab report

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Chemical Equations to Lab
Reaction Chemical Equation
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Types of Chemical Reactions

• 1. Synthesis (A B ----gt AB)
• 2. Decomposition (AB------gt A B)
• 3. Single Replacement (A BC ---gt B AC)
• 4. Double Replacement (AB CD ---gt CB AD)
• 5. Combustion (CxHx O2 ----gt CO2
  H2O)
• 6. Neutralization (Acid Base--gt H2O Salt)

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Chemical Equations to Lab

• Just need to check and see if they are balanced.
• Mg O2 ------gt
• Mg HCl ----gt
• (NH4)2(CO3) -----gt NH3 CO2
  H2O
• Ca(CO3) HCl ----gt CaCl2 H2O
  CO2
• Zn CuCl2 ----gt
• CuCl2 Na3(PO4) ---gt
• HCl Na(OH) ----gt H2O NaCl
• C2H6O O2 -----gt

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Chemical Reaction Review

• What are the coefficients that will balance the
  chemical equation below?
• AlCl3 Na(OH) ----gt Al(OH)3 NaCl
• 1,3,1,3
• 3,1,3,1
• 1,1,1,3
• 1,3,3,1
• What type of chemical reaction is in question 1?
• Predict the product and balance if needed
• Ba (s) O2 (g) ----------gt

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Balancing and Classifying Chemical Reactions
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Chemical Equations to Lab

• Just need to check and see if they are balanced.
• Mg O2 ------gt MgO
• Mg HCl ----gt MgCl H2
• (NH4)2(CO3) -----gt NH3 CO2
  H2O
• Ca(CO3) HCl ----gt CaCl2 H2O
  CO2
• Zn CuCl2 ----gt ZnCl2 Cu
• CuCl2 Na3(PO4) ---gt Cu3(PO4)2 NaCl
• HCl Na(OH) ----gt H2O NaCl
• C2H6O O2 -----gt CO2 H2O

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Conclusion

• Needs to include the following
• Identify and explain the types of reactions
  obsvd. ?
• Which reaction(s) did you like the best and why?
• Based on data section explain which reactions
  were exothermic and endothermic.
• What did you learn from this lab?

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Infinite Campus Update

• Chemical Reaction Lab (20pts.)
• Balancing Chemical Equation Wksht.(10pts.)

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Chemical Reaction Review

• 1. Classify the type or reaction and balance if
  needed
• a. C6H12 O2 ---------gt CO2 H2O
• b. LiCl ------gt Li Cl2
• c. H2(SO3) Al(OH)3 -------gt H2O
  Al2(SO3)3

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Predicting Products in a Chemical Reaction

• Ca N2 --------gt ?
• b. Cu2S -------gt ?
• NaBr F2 ------gt ?
• CH4 O2 -----gt

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Balancing and Classifying Equations Quiz

• Types of Chemical Reactions
• 1. Synthesis
• 2. Decomposition
• 3. Single Replacement
• 4. Double Replacement
• 5. Combustion
• 6. Neutralization

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Predicting Products

• Check my webpage for correct chemical formulas
• prior to balancing.

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Predicting Single Replacement Reactions

• An Activity Series can help us predict if a
  single replacement reaction will take place.

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Activity Series Lab Hypothesis
CuCl2(aq) Ag(NO3) HCl (aq) dH(OH) (l)
Copper (s)
Magnesium (s)
Zinc (s)
Calcium (s)
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Activity Series Lab

• Complete conclusion
• Complete Post Lab Questions

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Activity Series Lab

• Using the Activity Series Table, predict whether
  the following single replacement reactions would
  occur
• Li MgCl
• b. Hg Na3P
• c. Pb HF

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Chemical Reactions Study Guide

• Chpt. 9.4 Acids and Bases
• Chpt. 11 Balancing, Classifying, and Predicting
  Chemical Reactions
• Chpt. 18.1 Reaction Rates

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Predicting Single Replacement Reactions

• An Activity Series can help us predict if a
  single replacement reaction will take place.

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Predicting Single Replacement Reactions

• 1. Determine which single replacement reactions
  below can occur using your Activity Series
  diagram
• K MgCl2
• Al Li3(PO4)
• Sn2 HCl
• Ag HCl
• Pb4 H2(SO3)

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Chemical Reaction Study Guide Changes

• Vocabulary words Thermochemistry
• 10. HgO energy ------gt Hg O2
• 11. Fe F2 ----------gt FeF3 energy
• CH4 O2 ---------gt CO2 H2O energy
• K(OH) H3(PO4) -------gt
• 18. Omit last word equation. ?

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Chemical Reaction Review

• What are the coefficients that will balance the
  chemical equation below?
• AlCl3 Na(OH) ----gt Al(OH)3 NaCl
• 1,3,1,3
• 3,1,3,1
• 1,1,1,3
• 1,3,3,1
• What type of chemical reaction is in question 1?
• Predict the product and balance if needed
• BaS Mg ----------gt

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Thermochemistry

• Energy changes that occur within reactions.

Endothermic Reactions
Exothermic Reactions
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Exothermic Reaction

• Energy absorbed lt Energy released.
• The chemical reaction becomes cooler and its
  surroundings gets warmer.
• Energy is on the product side.
• C8H18 O2 -------gt CO2 H2O energy

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Endothermic Reactions

• Energy absorbed gt Energy released
• Chemical reaction gets warmer and its
  surroundings gets cooler.
• Energy is on the reactant side.
• Ex. Photosynthesis

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Chemical Reaction Review

• Using the Activity Series diagram would the
• following reactions take place?
• a. Al Cu(OH)
• Ag HCl
• Classify the type or reaction and balance if
  needed
• a. C6H12 O2 ---------gt CO2 H2O
• b. LiCl ------gt Li Cl2
• c. H2(SO3) Al(OH)3 -------gt H2O
  Al2(SO3)3

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Endothermic vs. Exothermic
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Infinite Campus Update

• Chemical Reaction Lab(20pts.)
• Activity Series Lab (10pts.) (1,2,4,6)
• Balancing Chemical Equation Wksht.(10pts.)
• Word Equation Worksheet (10pts.)

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Infinite Campus Update

• Chemical Reaction Lab(20pts.)
• Balancing Chemical Equation Wksht.(10pts.)
• Word Equation Worksheet (10pts.)

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Bell Ringer Thermochemistry

• Classify as exothermic (Ex) or endothermic.
  (Endo)
• C8H18 O2 -------------gt CO2 H2O
  energy
• BaBr2 energy -----------gt Ba Br2
• 2. During an experiment you observed the test
  tube getting cooler. Explain why this is
  happening including the terms system and
  surroundings.
• Using the activity series determine which
  reactions will occur in nature
• Mg FeCl2
• Cu K(OH)
• Al H2(CO3)

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Thermochemistry Wksht

• Work on question 2 on Thermochemistry wksht.

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Chemical Reaction Energy Diagram
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Chemical Reaction Energy Diagram

• Activation Energy (Ea) The amount of kinetic
  energy
• needed to be absorbed by the reactants in order
  for
• the chemical reaction to occur.

H The amount of kinetic energy released into
the surroundings.
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Chemical Reaction Energy Diagram
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Chemical Reaction Energy Diagram
Activation Energy
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Chemical Reactions Objectives

• 1.Classify and name compounds in chemical
  reactions
• 2.Describe chemical reactions in word and
  chemical equations.
• 3.Balance chemical equations based on the Law of
  Conservation of Mass.
• 4.Identify and classify types of chemical
  reactions and energy changes involved.
• 5.Predict products and energy changes in a
  chemical reaction.
• 6.Identify and test factors that affect the rate
  of chemical reactions. (Chpt. 18.1)

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Chemical Reaction Rates

• Assignment
• Read Section 18.1 in textbook (pg. 540)

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Chemical Reactions Rates

• Reaction Rates how fast the reactants
  chemically change into the products.
• Collision Theory Reactant particles will form
  products when reactants collide
• at the right position.
• and exchange the right amount of kinetic energy.
  

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Rates of Chemical Reactions

• What are factors that can affect the speed of a
  reaction?

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Rates of Chemical Reactions

• What are factors that can affect the rates of
  reactions?
• Temperature
• Concentration of Reactants
• Surface Area of Reactants
• Catalysts
• Inhibitors

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Temperature of Reaction

• What if we increase the temperature of a
  reaction?
• What if we decrease the temperature of a reaction?

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Concentration

• Increase concentration of reactants?
• Decrease concentration of reactants?

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Surface Area

• Increase surface area of reactants?
• Decrease surface area of reactants?

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Catalysts

• Catalysts speed up reactions, but they are not
  apart of the chemical reaction.
• Ex. Enzymes keep your body temperature around
  37oC (98 oF) by speeding up important biological
  reactions.

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Catalyst and Energy Change
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Inhibitors

• Inhibitors slow down a chemical reaction.
• Inhibitors bind to a catalyst and prevent it from
  speeding up a reaction.
• Ex. Preservation of food. Antioxidants prevent
  foods from becoming stale or moldy.

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Soln. A Concentration vs. Avg. Reaction Times
Time Conc G1 G2 G3 G4 G5 G6 G7 Avg.
A1 (100) 15 20 35 16 37 22 25
A2 (75) 19 24 38 20 31 44 28
A3 (50) 25 33 37 22 25 65 28
A4 (25) 50 39 34 29 38 78 34
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Activation Energy

• Activation energy minimum energy colliding
  reactants must have for a reaction to occur.
  (Energy hump.)

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Chemical Reactions Study Guide

• Chpt. 9.4 Acids and Bases
• Chpt. 11 Balancing, Classifying, and Predicting
  Chemical Reactions
• Chpt. 18.1 Reaction Rates

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Infinite Campus Update

• Classifying Chemical Reaction lab (20pts.)
• Activity Series Lab (10pts.)
• Starch Iodine Lab (10pts.)-due Wed.
• ACT Test for Juniors Tomorrow, March 6th
• End of quarter Thursday, March 8th

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Chemical Reaction Study Guide
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Catalyst and Energy Change
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Infinite Campus Updated

• Activity Series Lab (10pts)
• Classifying Chemical Reaction Lab (15pts)
• (Do NOT throw away-Formal Lab Report)
• Starch-Iodine Reaction Lab w/graph. (15pts)
• Quarter End Tomorrow, March 8th
• (All assignments by Friday).

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Formal Lab Report

• Due March 14th (next Wed.)
• Written (legible) or Typed (save to flashdrive)