This document provides information about chemical reactions, including signs that a reaction has occurred and different types of reactions. It discusses synthesis reactions where two or more compounds combine to form a new substance, decomposition reactions where a single compound breaks down into simpler substances, and displacement reactions where one element replaces another. It emphasizes that chemical reactions result in new substances with different properties. Balancing chemical equations is also covered, following the law of conservation of mass. A sample lab procedure on mixing borax solution and glue is presented to demonstrate a chemical reaction.

1. Chemical Reactions
Chapter 14

2. When a chemical goes
through a Chemical
Reaction one or more
substances are changed to
new substances

3. Signs of Chemical Reactions
Gas Formation
Solid Formation (called precipitate)
Energy is released
 Heat

Light

Electricity
Energy taken in
Color change
Most important: The formation of a new
substance that has different properties.

5. Not all signs happen for
each reaction and some are
subtle

6. Chemical and Physical
Properties change!

7. Chemical Reaction Lab

8. Question
??

9. Hypothesis
??

10. Materials
Glass container with ¼ cup Hydrogen
Peroxide.
2 Square inches of steel wool.
Stopper
Balloon

11. Steps
Write 1-2 paragraphs on your observation
of the materials provided.
Put balloon over rubber stopper.
Place Steel Wool into glass container.
Place rubber stopper firmly over the
opening of the glass container.
Place on counter and make daily written
observations.

12. Conclusions
How did you know that a chemical
reaction took place? (what signs of a
chemical reaction did you observe?)

13. Finished Lab
Typed in order
Follow our lab format
Be complete and include observation
data.
Due _____________.

14. Homework
Read p 388-391
Section Review p 391

15. Quiz
Define Chemical Reaction:
What is a precipitate?
List 2 signs of a chemical reaction:
T/F Steam from a teapot means a
chemical change has taken place.
T/F During a Chemical reaction the bonds
are broken and the atoms rearrange with
new bonds.

16. Answers
The process by which one or more
substances change to produce a new or
different substance.
A solid formed by a chemical reaction in a
solution.
Gas, Energy, Precipitate, Color, New
Substance.
F
T

17. Types of Chemical
Reactions
A process by which one or more
substances change to make one
or more new substances.

18. Synthesis Reactions
Two or more compounds combine
to form a new substance.

19. Decomposition
Reactions
A single compound breaks down
to form two or more simpler
substances.

20. Single-Displacement
Reactions
One element or radical takes the
place of another in a compound.

21. Cu + 2AgNO3 2Ag+Cu(NO3)2

22. Double-Displacement
Reaction
A gas, a solid precipitate, or a
molecular compound forms from
exchanging ions.

23. NaCl + AgF NaF + AgCl

24. Definitions
Reactants: The starting material in a
chemical reaction.
Products: The new substance formed
from a chemical reaction.

25. Law of Conservation of
Mass
Antoine Lavoisier (1790)
Mass cannot be created or destroyed in
ordinary chemical and physical
changes.
The total mass never changes

26. Homework
Read p 398-401
Section Review p 401

27. Quiz
What is a synthesis reaction?
What is a decomposition reaction?
What are single-displacement reactions?
What are double-displacement reactions?

28. Answers
2 or more substances combine to form a new
compound
A reaction in which a single compound breaks
down to form 2 or more simpler substances.
A reaction in which one element or radical takes
the place of another element or radical in the
compound.
A reaction in which a gas, a solid precipitate, or
a molecular compound forms from exchange of
ions between 2 compounds.

29. Balancing Chemical
Equations

30. Counting Atoms
4Al2(SO4)3
8 Aluminum
12 Sulfur
48 Oxygen

31. You Try
2Na3PO4

32. Steps
1. Count the Atoms
2. Place a coefficient in front of the second
part if the equation if necessary
3. Place a coefficient in front of the first part
of the equation to balance the atoms.
 Atoms from the left side must equal the
atoms from the right side of the equation.

33. ___AlBr3 + ___K ___KBr + ___Al

34. ___AlBr3 + ___K _3_KBr + ___Al

35. ___AlBr3 + _3_K _3_KBr + ___Al

36. _1_AlBr3 + _3_K _3_KBr + ___Al

37. _1_AlBr3 + _3_K _3_KBr + _1_Al

38. ___Mn + ___HI ___H2 + ___MnI3
2 Mn + 6 HI >>> 3 H2 + 2 MnI3

39. ___AlBr3 + ___K2SO4 ___KBr +___Al2(SO4)3
2 AlBr3 + 3 K2SO4 >> 6 KBr + 1 Al2(SO4)3

40. Homework
Read p 392-397
Section Review p 397

41. Quiz
How many atoms are in C14HgCl5?
Define Reactant:
Define Product:
What is the Law of Conservation of Mass?
Balance:
 ___Na + ___Cl2 >>> ___NaCl2

42. Answers
28
The starting material in a chemical
reaction.
Substances formed from a chemical
reaction.
Mass is neither created or destroyed in
ordinary chemical and physical changes.
Na + 1 Cl2 >>> NaCl2

43. Chemical Equations
Sheet 1

44. Homework
Read p 402-407
Section Review p 407

45. Chemical Equations
Sheet 2

46. p 410
1-15 all, 21, 22

47. Chemical Reaction Lab

48. Question
??

49. Hypothesis
??

50. Materials
White Glue
Borax solution, 40g/L
Paper cup and stirrer
Rubber gloves
Goggles
Plastic bag

51. Steps
Write observations of each material.
Place the Borax solution in the white glue.
Stir and mix well.
Place new mixture in plastic bag.
Write final observations.

52. Observations
What is each material like. Consistency, state,
appearance, etc.
What happen when they were mixed together?
Compare the properties of the glue with the new
substance.
Predict the properties of the material if less
Borax is used.
How do you know a chemical reaction took
place?

53. Conclusion
Two Paragraphs

Did the experiment support your hypothesis
and why?
 What did you learn?

54. Final lab write up
Follow as we have all year.
Due: ___________