1. Chemical Reactions
Chapter 7

2. Chapter 7 Day 1 Do Now: Chapter 7 Vocabulary
OBJECTIVE: Interpret chemical reactions for reactants and products, energy needs and conservation of mass.
Do Now:
Chapter 7 Vocabulary
TURN IN: Model Molecule Lab
Today:
Chapter 7 – Chemical Reactions notes
Types of Chemical Reactions
Cartoon Chemistry
Homework:
Finish Cartoon Chemistry

3. Unit 2 Chapter 7 Day 2 OBJECTIVE:
Unit 2 Chapter 7 Day 2 OBJECTIVE: Interpret chemical reactions for reactants and products, energy needs and conservation of mass.
Do Now:
Types of Chemical Reactions
Today:
The Balancing Act packet – Notes and Worksheets
Homework:
Balancing Equations

4. Unit 2 Chapter 7 Day 3 OBJECTIVE: Interpret chemical reactions for reactants and products, energy needs and conservation of mass.
Do Now:
Balancing Review
Today:
Homework review – Balancing Equations
DVD Field Trips – Chapters 6 & 7
Test review / Study Guide… What did we learn again?
START Test Review packet
Homework:
COMPLETE Test Review packet

5. Unit 2 Chapter 7 Day 4 OBJECTIVE:
Unit 2 Chapter 7 Day 4 OBJECTIVE: Demonstrate knowledge of matter, phase, atomic structure, the periodic table, chemical reactions and conservation of mass.
Do Now:
Vocabulary Bingo - Chapters 4,5,6,7
Today:
Review Chemistry Unit Study Guide
Spring Balance Challenge
Homework:
STUDY FOR CHEMISTRY UNIT TEST

6. Unit 2 Chapter 7 Day 5 Do Now: Do Now Folder #6-7 (8 pages) Today:
OBJECTIVE: Demonstrate knowledge of matter, phase, atomic structure, the periodic table, chemical reactions and conservation of mass.
Do Now:
Do Now Folder #6-7 (8 pages)
Today:
Chemistry Unit Test
Unit 2 Notebook Chap 6 & 7 (21 pages)
Homework:
Current Events – 2nd Chance Experiments

7. Extra Credit Balance Challenges
____ CoBr3 + ____ CaSO4  ____ CaBr2 + ____ Co2(SO4)3
____ S    +   ____ HNO3       ____ H2SO4   +    ____ NO2   +   ____ H2O 
____ Cu   +  ____  HNO3    ____ Cu(NO3)2  + ____ NO   +    ____ H2O

8. A 2 CoBr3 + 3 CaSO4  3 CaBr2 + Co2(SO4)3 B S + 6 HNO3 -> H2SO4 + 6 NO2 + 2 H2O C 3 Cu + 8HNO3 -> 3 Cu(NO3)2 + 2 NO + 4 H2O

9. Chemical Reactions
Chapter 7

10. Wednesday 11/12 and Thursday 11/13
Unit 2 Chapter 6/7
OBJECTIVE: Investigate five indicators of chemical reations.
Do Now:
ASK Review
Today:
Identifying Chemical Reaction Lab
Homework:
Missing Assignments for MP1?

11. Indicators of chemical reactions
Emission of light or heat
Formation of a gas
Formation of a precipitate
Color change
Emission of odor

13. All chemical reactions:
Create 1 or more new substances
Have two parts
Reactants - the substances you start with
Products- the substances you end up with
The reactants turn into the products.
Reactants ® Products

14. In a chemical reaction…
Bonds between atoms in reactants are broken
Atoms rearrange and form new bonds in the products
Atoms aren’t created or destroyed…Mass is CONSERVED in a chemical reaction..This is called… Law of Conservation of Mass

15. Reaction Energy
All chemical reactions are accompanied by a change in energy.  It takes energy to break bonds AND energy is released when bonds are broken!
Exothermic
- reactions that release energy to their surroundings (usually in the form of heat)
Endothermic - reactions that need to absorb heat from their surroundings to proceed.

16. Types of Reactions

17. Synthesis Reactions
TWO elements combine to make one compound. (Polyatomics count as one)
A + B ® AB
Na + Cl2 ® NaCl
Ca +O2 ® CaO SO3 + H2O ® H2SO4
We can predict the products if there are two elements.
Mg + N ®
Mg3N2

18. Decomposition Reactions
decompose = fall apart, Falls apart into its elements
Made up of only two elements
one compound (reactant) falls apart into two or more elements or compounds.
Usually requires energy
AB ® A + B
NaCl ® Na + Cl2
CaCO3 ® CaO + CO2

19. Single Replacement One element replaces another
Reactants must be an element and a compound.
Products will be a different element and a different compound.
A + BC ® AC + B
2Na + SrCl2 ® Sr + 2NaCl
F2 + LiCl ® LiF + Cl2

20. Double Replacement Two things replace each other.
Usually in water solution
AB + CD ® AD + CB
ZnS HCl ®
ZnCl + H2S
AgNO3 + NaCl ®
AgCl + NaNO3

21. How to recognize which type
Look at the reactants
Element(E), Compound(C)
E + E C
E + C
C + C
Synthesis
Decomposition
Single replacement
Double replacement

22. Examples Synthesis H2 + O2 ® H2O ® Decomposition AgNO3 + NaCl ®
Double replacement
Zn + H2SO4 ®
Single replacement
HgO ®
Decomposition
KBr +Cl2 ®
Single replacement
Mg(OH)2 + H2SO3 ®
Double replacement

23. Examples Decomposition CaPO4 ® AgBr + Cl2 ® Single replacement
Zn + O2 ®
Synthesis
HgO + Pb®
Single replacement
Cu(OH)2 + KClO3 ®
Double replacement

24. Identifying Chemical Reactions
S = Synthesis D = Decomposition SR = Single Replacement DR = Double Replacement
_____ P O2 → P4O10
____ Mg O2 → MgO
____ HgO → Hg O2
____ Al2O3 → Al O2
____ Cl NaBr → NaCl Br2
____ H N2 → NH3

25. ____ Na Br2 → NaBr
____ CuCl H2S → CuS HCl
____ HgO Cl2 → HgCl O2
____ C H2 → CH4
____ KClO3  →   KCl  +  O2 
____ S F2 → SF6
____ BaCl2   +   Na2 SO4 →    NaCl   + BaSO4

26. Balancing Act

27. Chemical Reactions Review…
Is the process where physical and chemical properties of the original substance change into a new substance with different physical and chemical properties
If there is no new substance there has been no reaction
Reactants enter into the reaction
Products are produced by the reaction

28. Chemical Reactions Review…
Chemical equations describe chemical reactions using symbols and numbers.
2Na + SrCl2 ® Sr + 2NaCl
Coefficients (in red)
The large numbers in front of chemical formulas.
The number of molecules of the substance in the reaction

29. Chemical Reactions Review…
Chemical equations describe chemical reactions using symbols and numbers.
2Na + SrCl2 ® Sr + 2NaCl
Subscripts (in Green)
The small numbers to the lower right of chemical symbols
Represent the number of atoms of each element is in the molecule

30. Chemical Reactions Review…
Atoms can neither be created nor destroyed during a chemical reaction…Mass MUST remain constant
You have to end up with the same number of atoms you started with, but in a different arrangement
So balanced equations have the same number of atoms on each side of the YIELDS “®“ sign
Law of Conservation of Mass

31. Balancing Chemical Equations (ALWAYS USE PENCIL)
Check for DIATOMIC molecules H2 , N2 , O2 , F2 , Cl2 , Br2 , I2 , and At2
You cannot change the subscripts of these elements in an equation… whenever they are by themselves, these must be written with the subscript 2.

32. Balancing Chemical Equations
Count the number of atoms on each side of the reaction:
___Na + ___MgCl2 ® ___Mg + ___NaCl
Sodium=____ ® Sodium=____
Magnesium=____ ® Magnesium =____ Chlorine=____ ® Chlorine=____ 1 2 1

33. Balancing Chemical Equations
Balance the metals first then the nonmetals
___Na + ___MgCl2 ® ___Mg + ___NaCl
Sodium=____ ® Sodium=____
Magnesium=____ ® Magnesium =____ Chlorine=____ ® Chlorine=____ 2 2 1 2
X 2 1
X 2
X 2

34. Balancing Chemical Equations
If they are in your equation, balance OXYGEN then HYDROGEN last
Recount all atoms and check your work!
Work from the bottom to top until you find any error.
If every coefficient will reduce, rewrite in the simplest whole number ratio

35. Balancing Chemical Equations
Lets try an easy one:
___H2 + ___O2 ® ___H2O
Hydrogen=____ ® Hydrogen=____
Oxygen=____ ® Oxygen =____ 2 2 2 1
X 4 2
X 4
X 2

36. Balancing Chemical Equations
Lets try one more:
___Na + ___HCl ® ___H2 + ___NaCl
Sodium=____ ® Sodium =____
Hydrogen=____ ® Hydrogen=____
Chlorine=____ ® Chlorine =____ 2 2 2 1
X 2 1 2
X 2
X 2
X 2
X 2

37. Balancing Act ___Mg + ___O2 ® ___MgO ___Ca + ___O2 ® ___CaO
___H2O2 ® ___H2O + ___O2
___N2 + ___H2 ® ___NH3
___Cu2O + ___C ® ___Cu+ ___CO2

39. Reaction Energy
Spontaneous Reactions - Reactions that proceed immediately when two substances are mixed together.  Not all reactions proceed spontaneously. 
Activation Energy – the amount of energy that is required to start a chemical reaction.
Once activation energy is reached the reaction continues until you run out of material to react.  

41. Diatomic elements
There are 8 elements that never want to be alone.
They form diatomic molecules.
H2 , N2 , O2 , F2 , Cl2 , Br2 , I2 , and At2

42. What is a catalyst?
A substance that can help the reactants in a chemical reaction react with each other faster
Speeds up a reaction without being changed by the reaction…it does NOT become part of the reaction.
Enzymes are biological or protein catalysts.

43. Summary of Symbols