1. Types of Chemical Reactions

2. Evidence of Chemical Reactions 1.Change in colour 2.Change in odour 3.Formation of a gas 4.Formation of a precipitate 5.Release or absorption of energy (e.g. heat or light)

3. Types of Chemical Reactions We will learn about 6 types of chemical reactions 1.Synthesis 2.Decomposition 3.Combustion 4.Single Displacement 5.Double Displacement 6.Neutralization

4. Subscripts for States of Matter We can identify the physical state of a substance using subscripts (s) = solid (g) = gas (l) = pure liquid (aq) = aqueous solution (dissolved in water)

5. Synthesis Reactions Smaller atoms/molecules combine to form larger molecules A + B  AB 2H 2(g) + O 2(g)  2H 2 O (l)

6. Synthesis Reaction +

7. Decomposition Reaction The splitting of a large molecule into elements or smaller molecules AB  A + B 2H 2 O (l)  2H 2(g) + O 2(g) Complimentary to synthesis reaction

8. Decomposition Reaction +

9. Combustion Fuel (hydrocarbons) burned in the presence of oxygen to produce a carbon dioxide, water and heat energy C x H y + O 2  CO 2 + H 2 O + heat C 4 H 10(l) + O 2(g)  CO 2(g) + H 2 O (l) + heat

10. Incomplete Combustion Occurs when fuel is not completely converted into carbon dioxide and water Can result in the production of toxic carbon monoxide C 4 H 10(l) + O 2(g)  C (s) + CO (g) + CO 2(g) + H 2 O (g) sootpoisonous

11. Single Displacement One element replaces another element from a compound A + BC  AC + B Mg (s) + 2AgNO 3(aq)  2Ag (s) + Mg(NO 3 ) 2(aq) Note: A metal can only replace a metal and a nonmetal can only replaces a nonmetal

12. Single Displacement

13. ++

14. The Activity Series If the single element is above the element in the compound, a single displacement reaction will occur.

15. Examples a)aluminum + nickel (II) chloride b)lead + zinc nitrate c)fluorine + sodium bromide

16. Double Displacement Positive ions (cations) in different compounds replace each other AB + CD  AD + CB Pb(NO 3 ) 2(aq) + 2KI (aq)  PbI 2(s) + 2KNO 3(aq)

17. Double Displacement

18. + +

19. Solubility Rules Most double displacement reactions involve aqueous solutions of ionic compounds For a reaction to occur, a precipitate (insoluble solid) must form To predict which ionic compounds will be soluble, and which will form precipitates (insoluble) we must use the solubility rules: 1.All compounds with nitrate (NO 3 - ) are soluble 2.All compounds with ammonium (NH 4 + ) are soluble 3.All compounds with group 1 metals are soluble 4.Most other compounds are insoluble (will form a precipitate)

20. Solubility Table …Or use a solubility table

21. Examples a)sodium carbonate + barium nitrate  b)lithium hydroxide + ammonium chlorate 

22. Neutralization A special type of double displacement reaction Acid + Base  Salt + H 2 O (ionic compound) HCl (aq) + NaOH (aq)  NaCl (aq) + H 2 O (l)