1. QOTD  Explain the relationship between the law of conservation and chemical reactions.

3.  Synthesis  Decomposition  Neutralization  Single displacement  Double displacement  Combustion

4. A chemical change: any change in which a new substance is formed. Evidence of a Chemical Change:  Release of energy as heat  Release of energy as light  Change in color  Formation of a gas  Change in odor…

5. 1.Neutralization: Acid(H) + Base(OH)  salt + H(OH) 2.Combustion: AB + oxygen  CO 2 + H 2 O 3.Synthesis: A + B  AB 4.Decomposition: AB  A + B 5.Single displacement: A + BC  AC + B 6.Double displacement: AB + CD  AD + CB

6. Synthesis Reactions  Synthesis reactions are also known as FORMATION reactions.  Two or more reactants (usually elements) join to form a compound.  A + B  AB where A and B represent elements

7. Synthesis

8. Decomposition Reactions  Decomposition reactions are the opposite of synthesis reactions.  A compounds breaks down into two or more products (often elements).  AB  A + B

9. Decomposition Reactions

10. Types: Decomposition Example: NaCl General: AB  A + B  Cl Na Cl + Na

11. Single Replacement Reactions  Single replacement reactions replace one element from a compound with another element.  A compound and an element react, and the element switches places with part of the original compound.  A + BC  B + AC where A is a metal, or  A + BC  C + BA where A is a non-metal

12. Single replacement

13. Double Replacement Reactions  Double replacement reactions swap elements between 2 compounds that react together to form two new compounds.  Two compounds react, with elements switching places between the original compounds.  AB + CD  AD + CB

14. Double Replacement Reactions

15. Neutralization  Neutralization reactions occur when an acid (most compounds starting with H) and a base (most compounds ending in OH) react to form a salt and water.  Neutralization reactions are a type of double replacement.  Acid + base  salt + water

16. Combustion  Combustion reactions occur when a compound or element react with oxygen to release energy and produce an oxide.  Also sometimes referred to as hydrocarbon combustion.  CXHY + O2  CO2 + H2O  where X and Y represent integers

17. Combustion  Natural gas (methane) is burned in furnaces to heat homes.  CH4 + O2  CO2 + 2H2O + energy  2. An acetylene torch is used to weld metals together.  2C2H2 + 5O2  4CO2 + 2H2O + energy  3. Carbohydrates like glucose combine with oxygen in our body to release energy.  C6H12O6 + 6O2  6CO2 + 6H2O + energy

18. (c) McGraw Hill Ryerson 2007