1. Chemical Reactions and Equations

2. Definition
A chemical reaction is the process by which one or more substances change into one or more new substances whose chemical and physical properties differ from those of the original substances.

3. Writing a Chemical Reaction
Reactants are the elements or compounds you begin with
Products are the elements or compounds you end with
Reactants Products
“yield”

4. Numbers H+1 P-3 H2O C6H12O6 2NaCl 5H2O
Superscripts show the charge of an ion
Subscripts show the # of atoms in a compound
Coefficients show the # of molecules
H P-3
H2O C6H12O6
2NaCl 5H2O

5. Fill in the Blanks
Yields
Reactants
Product
Subscript
Coefficient

6. Symbols

7. Symbols (cont.)

8. Symbols (cont.)

9. Signs of a Chemical Change
A solid
precipitate
is formed
A gas is
produced

10. Signs of a Chemical Change
Color
Change
Temperature
Change

11. Types of Chemical Reactions
Synthesis
Decomposition
Single Replacement
Double Replacement
Combustion

12. Synthesis
A synthesis reaction starts with two or more reactants and ends up with one product.

13. Magnesium + Oxygen  Magnesium oxide
Synthesis
Magnesium + Oxygen  Magnesium oxide
2Mg + O2  2MgO

14. Sodium + Chlorine gas  Salt
Synthesis
Sodium + Chlorine gas  Salt
2Na + Cl2  2NaCl

15. Decomposition
A decomposition reaction starts with one reactant and ends up with two or more products.

16. Decomposition
Calcium carbonate decomposes to produce calcium oxide and carbon dioxide.
CaCO3  CaO + CO2

17. Single Replacement
A single-replacement reaction starts with two reactants and ends up with two products. An element takes the place of another element that’s in a compound.

18. Single Replacement 2Al + 3CuCl2  3Cu + 2AlCl3
Aluminum foil is placed in a solution of copper II chloride which produces copper metal and aluminum chloride solution.
2Al + 3CuCl2  3Cu + 2AlCl3

19. Double Replacement
A double-replacement reaction starts with two reactants and ends up with two products. In this case both reactants and products are compounds. They simply change partners.

20. Double Replacement 2NaCl + Pb(NO3)2  2NaNO3 + PbCl2
A solution of sodium chloride is mixed with a solution of lead nitrate resulting in the production of sodium nitrate and lead chloride.
2NaCl + Pb(NO3)2  2NaNO3 + PbCl2

21. Combustion
A combustion reaction always involves a hydrocarbon and oxygen as reactants and ends up with carbon dioxide and water as products.

22. What type of reaction is this?
2H2O  2H2 + O2
Synthesis
Decomposition
Single Replacement
Double Replacement

23. What type of reaction is this?
4P + 5O2  P4O10
Synthesis
Decomposition
Single Replacement
Double Replacement

24. What type of reaction is this?
2MgO  2Mg + O2
Synthesis
Decomposition
Single Replacement
Double Replacement

25. What type of reaction is this?
BaCl2 + H2S  BaS + 2HCl
Synthesis
Decomposition
Single Replacement
Double Replacement

26. What type of reaction is this?
2Al2O3  4Al + 3O2
Synthesis
Decomposition
Single Replacement
Double Replacement

27. What type of reaction is this?
Cl2 + 2NaBr  Br2 + 2NaCl
Synthesis
Decomposition
Single Replacement
Double Replacement

28. What type of reaction is this?
3H2 + N2  2NH3
Synthesis
Decomposition
Single Replacement
Double Replacement

29. What type of reaction is this?
CaCl2 + 2KBr  2KCl + CaBr2
Synthesis
Decomposition
Single Replacement
Double Replacement

30. What type of reaction is this?
H2O + MgO  Mg(OH)2
Synthesis
Decomposition
Single Replacement
Double Replacement

31. What type of reaction is this?
2NH4CO3  2NH3 + H2O + CO2
Synthesis
Decomposition
Single Replacement
Double Replacement

32. What type of reaction is this?
Cu + AgNO3  Ag + CuNO3
Synthesis
Decomposition
Single Replacement
Double Replacement

33. What type of reaction is this?
2Al + 3CuCl2  3Cu + 2AlCl3
Synthesis
Decomposition
Single Replacement
Double Replacement

34. What type of reaction is this?
C + 2H2  CH4
Synthesis
Decomposition
Single Replacement
Double Replacement

35. What type of reaction is this?
3NiO + 2Li3P  3Li2O + Ni3P2
Synthesis
Decomposition
Single Replacement
Double Replacement

36. What type of reaction is this?
CuCl2 + H2S  2HCl + CuS
Synthesis
Decomposition
Single Replacement
Double Replacement

37. What type of reaction is this?
2H3PO4  3H2O + P2O5
Synthesis
Decomposition
Single Replacement
Double Replacement

38. What type of reaction is this?
2Na + FeO  Fe + Na2O
Synthesis
Decomposition
Single Replacement
Double Replacement