1. Types of Chemical Reactions
Section 3.3

2. Overview At the end of this lesson you will be able to:
Predict the products of five types of chemical reactions, given the reactants and balance the resulting chemical equation

3. Review What is the formula for the following compounds?
Magnesium nitrate
Potassium iodide
Calcium phosphate
Nitrogen trichloride
Carbon dioxide
What ions can combine?
How do we find state of ionic compounds?

4. Types of Chemical Reactions
There are five types of chemical reactions:
Formation
Decomposition
Combustion
Single replacement
Double replacement
What do you think each of these mean? Any guesses?

5. Formation Reactions Also called synthesis reaction
Simplest form, two elements combine to form a compound
Element + element  compound
A + B  AB
Ex. S8(s) + 8O2(g)  8SO2(g)

6. Formation Reactions Can be more complex
Compound + compound  compound
Ex. CO2(g) + H2O(l)  H2CO3(aq)
For more complex formation reactions where one reactant is a metal and one a non-metal, write the ionic compound that would be formed

7. Decomposition Reactions
Breaking down compounds into its constituent parts
Compound  element + element
AB  A + B
Only one reactant
Ex. 2 H2O(l)  2 H2(g) + O2(g)

8. Combustion Reactions Burning in the presence of oxygen
Exothermic? Endothermic?
The products are the oxides of the elements present in the reactants – compounds with oxygen bonded to another element
Generally, the product is most common oxide

9. Combustion Reactions Be familiar with these most common oxides:
carbon, then CO2(g) is formed
hydrogen, then H2O(g) is formed
sulfur, then SO2(g) is formed
nitrogen, then NO2(g) is formed
a metal, then the most common oxide of that metal is formed

10. Hydrocarbon Combustion
A type of combustion reaction
Hydrocarbon- substances containing hydrogen and carbon
General formula: CxHy (x= # carbons, y= # hydrogens)
Combine with O2(g) to make two products: CO2(g) and H2O(g)
CxHx + O2 (g) → CO2 (g) + H2O (g)
CH4 (g) + 2 O2 (g) → CO2 (g)+ 2 H2O (g)

11. Combustion Reactions C3H8(g) + 5 O2(g)→ 3 CO2(g) + 4 H2O(g)
Other combustion examples:
C3H8(g) + 5 O2(g)→ 3 CO2(g) + 4 H2O(g)
2 Na2S(s) + 3 O2(g)→ 2 Na2O(s) + 2 SO2(g)
4 Fe(s) + 3 O2(g) → 2 Fe2O3(s)
4 NH3(g) + 7 O2(g) → 4 NO2(g) + 6 H2O(g)

12. Single Replacement Reactions
Single element replaces another element in a compound
A + BC  B +AC
Mg(s) + 2 AgNO3(aq)  2 Ag(s) + Mg(NO3)2(aq)

13. Double Replacement Reactions
Element of each of two compounds switch places
AB + CD  AD + CB
Be careful!
Make sure only combining positive ions with negative ions (i.e. cannot put positive-positive together)
Positive ions appear first and negative ions second

14. Questions?

15. Predicting and Balancing
Double Replacement Reactions:
Aqueous lead(II) nitrate and aqueous sodium iodide are mixed and a yellow precipitate forms. Predict the products, writing out the balanced formula equation, including states

16. Practice
Write the formula equation, predict the products, and balance the following (include states!):
When aqueous copper(I) nitrate and aqueous potassium bromide are mixed, a precipitate forms
Aluminium chloride and sodium hydroxide are mixed, creating a precipitate
Ni(NO3)3(aq) + Na2SO3(aq) 

17. Practice: Single Replacement
Write the formula equation, predict the products and balance the following:
Aluminium metal and copper(II) chloride react together
Chlorine gas is added to a solution of aqueous nickel(III) bromide
Zinc metal is placed into a solution of silver nitrate

18. Practice: Decomposition
Predict the products and balance the following equations
___MgS(s) 
___KI(s) 
___Al2O3(s) 
___NiCl2(s) 

19. Practice: Formation
For the following equations give the product and balance
sodium + sulfur 
magnesium + oxygen 
Iron + chlorine 

20. Practice: Combustion ___CH4(g) + ___O2(g)  ___C2H6(g) + ___O2(g) 
Complete and balance each equation:
___CH4(g) + ___O2(g) 
___C2H6(g) + ___O2(g) 
___C3H8(g) + ___O2(g) 
___C6H6(l) + ___O2(g) 