1. Types of Chemical Reactions
Chemistry
Types of Chemical Reactions

2. Types of Chemical Reactions
Many chemical reactions have defining characteristics which allow them to be classified as a type.

3. Types of Chemical Reactions
Learning Targets:
Describe the five general types of reactions.
Predict the products of the five general types of reactions.

4. Types of Chemical Reactions
The five types of chemical reactions in this unit are:
Synthesis
Decomposition
Single Replacement
Double Replacement
Combustion
5 Types of Reactions Video

5. Synthesis Reactions
Two or more substances combine to form one substance.
The general form is A + X AX
Example:
Magnesium + oxygen  magnesium oxide
2Mg + O2  2MgO

6. Synthesis Reactions
Synthesis reactions may also be called composition or combination reactions.
Some types of synthesis reactions:
Combination of elements
K + Cl2  what is the product?
One product will be formed

7. Synthesis Reactions KCl 2K + Cl2  2KCl Write the equation K + Cl2 
Balance the equation:
KCl
2K + Cl2  2KCl

8. Synthesis Reactions Examples of synthesis reactions: SO2 + H2O  H2SO3
BaO + H2O  Ba(OH)2
Na2O + CO2  Na2CO3
CaO + SO2  CaSO3

9. Synthesis Reactions Elements or compounds combine to form ONE product
The only synthesis reactions you will be asked to determine would be the very simple ones with only 1 possible answer A + B = AB
(A is positive, B is negative)
E.g. K + Cl2 = KCl

10. Decomposition Reactions
One substance reacts to form two or more substances.
The general form is AX  A + X
Example:
Water can be decomposed by electrolysis.(don’ forget diatomic molecules)
2H2O  2H2 + O2

11. Decomposition Reactions
Examples of Decomposition Reactions:
CaCO3  CaO + CO2
H2CO3  H2O + CO2
Ca(OH)2  CaO + H2O
2KClO3  2KCl + 3O2
Zn(ClO3)2  ZnCl2 + 3O2

12. Decomposition Reactions
Some substances can easily decompose:
Ammonium hydroxide is actually ammonia gas dissolved in water.
NH4OH  NH3 + H2O
Some acids decompose into water and an oxide.
H2SO3  H2O + SO2

13. Decomposition Reactions
The only decomposition reactions you will be asked to determine would be the simple ones with only 1 possible answer
E.g. 2H2O  2H2 + O2

14. Types of Chemical Reactions
Single Replacement Reactions
Double Replacement Reactions
Combustion Reactions

15. Recall Synthesis Reactions
Two or more substances combine to form one substance.
The general form is A + X AX
Decomposition Reactions
One substance reacts to form two or more substances.
The general form is AX  A + X

16. Single Replacement Reactions
A metal(+) will replace a metal ion in a compound.
The general form is A+ +B+X-AX + B
A nonmetal(-) will replace a nonmetal ion in a compound.
The general form is Y-+B+X-  BY + X

17. Single Replacement Reactions
Examples:
Ni + AgNO3 
Nickel replaces the metallic ion Ag+ (metal replaces metal ion)
The silver becomes free silver and the nickel becomes the nickel (II) ion.
Ni + AgNO3  Ag + Ni(NO3)2
Balance the equation:
Ni + 2AgNO3  2Ag + Ni(NO3)2

18. Thermite Reaction
Thermite Video

19. Thermite Reaction Al + Fe2O3 
Aluminum will replace iron (III) as was seen in the video.
Iron (III) becomes Fe and aluminum metal becomes Al3+.
2Al + Fe2O3  2Fe + Al2O3

20. Double Replacement Reactions
Ions of two compounds exchange places with each other.
Reactants must be two ionic compounds, in aqueous solution
The general form is AX + BY  AY + BX

21. Double Replacement NaOH + CuSO4  The Na+ and Cu2+ switch places.
Na+ combines with SO42- to form Na2SO4.
Cu2+ combines with OH- to form Cu(OH)2
NaOH + CuSO4  Na2SO4 + Cu(OH)2
2NaOH + CuSO4  Na2SO4 + Cu(OH)2

22. Double Replacement CuSO4 + Na2CO3 
Cu2+ combines with CO32- to form CuCO3.
Na+ combines with SO42- to form Na2SO4.
CuSO4 + Na2CO3  CuCO3 + Na2SO4

23. Double Replacement Reactions
Think about it like “foil”ing in algebra, first and last ions go together + inside ions go together
Example:
AgNO3(aq) + NaCl(aq)  AgCl(s) + NaNO3(aq)
Another example:
K2SO4(aq) + Ba(NO3)2(aq)  KNO3(aq) + BaSO4(s) 2

24. Recognition
You need to be able to recognize which reaction is taking place

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

26. Classifying Chemical Reactions - Flintstones Video

27. Combustion Reactions Combustion means “add oxygen”
Normally, a compound composed of only C, H, (and maybe O) is reacted with oxygen – usually called “burning”
If the combustion is complete, the products will be CO2 and H2O.
If the combustion is incomplete, the products will be CO (or possibly just C) and H2O.

28. Combustion Reaction
When a substance combines with oxygen, a combustion reaction can result.
The combustion reaction may also be an example of an earlier type such as 2Mg + O2  2MgO.
An example of a combustion reaction is burning of fuel like gas or oil.

29. Combustion Reactions
Combustion reactions involve light and heat energy released.
Natural gas, propane, gasoline, etc. are burned to produce heat energy.
Most of these organic reactions produce water and carbon dioxide.

30. Combustion Reaction
When hydrocarbon compounds CxHx are burned in oxygen, the products are water and carbon dioxide.
CH4 + O2  CO2 + H2O
CH4 + 2O2  CO2 + 2H2O

31. Combustion Reactions
Generally combustion reactions involve the burning of a Hydrocarbon (CxHx) in Oxygen.
Other elements can also burn with Oxygen
2Mg + O2  2MgO + Energy
2H2 + O2  2H2O + Energy (basis behind fuel cell energy)
P4 + 5O2  P4O10 + Energy (matches)

32. So you want to make a product video

33. Practice Classify each of the following as to type: H2 + Cl2  2HCl
Synthesis
Ca + 2H2O  Ca(OH)2 + H2
Single replacement

34. Practice 2CO + O2  2CO2 2KClO3  2KCl + 3O2 Synthesis and combustion
Decomposition

35. Practice FeS + 2HCl  FeCl2 + H2S Zn + HCl  ? Double replacement
Single replacement
Zn + 2HCl  ZnCl2 + H2

36. End of Day 2
Types of Chemical Reactions Worksheet