1. Day 2 Types of Chemical Reactions p. 114 - 118

2. **You have to be able to predict the products
5 major reaction types
(there are more variations on these in reality)
Synthesis
Decomposition
Single replacement
Double replacement (including neutralizations)
Combustion
**You have to be able to predict the products
in each case **

3. Synthesis (aka combination)
A + B → AB Combining 2 or more substances to form a new compound eg. 2 Sb(s) + 3Br2(g) → 2SbBr3(g) H2(g) + Cl2(g) → HCl(g) try: C(s) + O2(g) → CO2(g)

4. Synthesis (aka combination)
How to Recognize:
only elements as reactants
Predicting products (for rxs involving 2 elements):
Assume product will be an ionic compound made of both elements (or something recognizable such as CO2)
Use the most common charges for each ion (the top one on the periodic table) when making your formula

5. common charge = top charge

6. Decomposition
AB → A + B = breaking down a molecule into simpler substances ( = chemical separation!) eg. 2 Ag2O(s) + heat → 4Ag(s) + O2(g) 2 HgO(s) + heat → 2Hg(l) + O2(g) try: 2 NO(g) + heat → N2(g) + O2(g)

7. Decomposition How to recognize: only one reactant!
Predicting products: Assume the reactant breaks into its component elements
try: H2O(l) → 2H2(g) O2(g)

8. Single Replacement AB + C → A + CB (if C is a metal)
AB C → AC B (if C is a non-metal)
= replacing one atom in a compound with another atom.
(like you are dancing with a friend and someone cuts in) someone is always single!
*Watch out for
Polyatomic ions*

9. Single Replacement How to Recognise:
Reactants = one element and one compound
Predicting Products:
The compound = metal + non-metal
The element may be either metal or non-metal
* Metals trade with metals
* Non-metals trade with non-metals

10. Single Replacement
eg. CuI2(s) + Br2(l) → CuBr2(s) + I2(s) try: Cl2(aq) + 2 KI(aq) → 2 KCl(aq) + I2(aq) try: 2 AgNO3(aq) + Cu(s) → 2 Ag(s) + Cu(NO3)2(aq)

11. (like two couples dancing and then a partner swap)
Double Replacement
AB CD → AD CB
= an exchange of atoms or groups between two different compounds
(like two couples dancing and then a partner swap)

12. Double Replacement eg. AgNO3(aq) + NaCl(aq) → AgCl(s) + NaNO3(aq)
Try: NaCl(aq) + H2SO4(aq) → 2 HCl(aq) + Na2SO4(aq)

13. Double Replacement How to recognize: two compounds react
Predicting products:
Assume the reactants are made up of ions
Swap positive ions
Watch charges when making new compounds
= nomenclature/formula writing!!**
Try: Cu(NO3)2(aq) Na2S(aq) → CuS(s) + 2NaNO3(aq)

14. Acid Base Neutralization = Double Replacement
Acid + Base → Salt + H2O Acid = chemical formula starts with H Base = chemical formula ends with OH Salt = ionic compound that is not an acid, or a base i.e. does not start with H does not end with OH

15. Acid or Base or Salt?? HCl KOH NaNO3 H2SO4 Ba(OH)2 Fe(OH)3 K2SO4 LiCl
Acid Base Salt

16. Acid Base Neutralization
e.g. HCl(aq) + NaOH(aq) → H2O(l) + NaCl(aq) Try: H2SO4(aq) + 2 KOH(aq) → K2SO4(aq) + 2 H2O(l) 2 H3PO4(aq) + 3 Sr(OH)2(aq) → Sr3(PO4)2(aq)+ 3 H2O(l)

17. Acid Base Neutralization
*** Notice that H2O = HOH (this should help you with your balancing) HCl(aq) + NaOH(aq) → HOH(l) + NaCl(aq) H2SO4(aq) + 2 KOH(aq) → K2SO4(aq) + 2 HOH(l) 2 H3PO4(aq) + 3 Sr(OH)2(aq) → Sr3(PO4)2(aq)+ 6 HOH(l)

18. Combustion
CxHyOZ + O2(g) → CO2(g) + H2O(g) = the rapid reaction of a substance with oxygen producing heat and often flames!

19. Combustion How to recognize: look for a hydrocarbon reactant (CxHyOZ)
Predicting Products:
you don’t have to! It will always be CO2(g) and H2O(g) but you do have to balance the rx!

20. C5H12(l) + 8 O2(g) → 5 CO2(g) + 6 H2O(g)
Combustion
Try:
C5H12(l) O2(g) → 5 CO2(g) H2O(g)
C5H12O2(l) O2(g) → 5 CO2(g) H2O(g) cv cv

21. Notes:
Add to your notes the table on page 118. Feel free to modify it in your own words
Practice:
p # 65, 66, 67 (especially 67)