1. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 1 Chapter 8 Chemical Equations and Reactions Sections 1 and 2 Describing Chemical Reactions Types of Chemical Reactions

2. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 2 Section 1 Describing Chemical Reactions

3. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 3 Oh, That Curious Ira Remsen! 1846-1927

4. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 4 Ira Remsen Demo Cu (s) + HNO 3 (aq)  CuNO 3 (aq) + H 2 (g) Chemical Reactions http://www.metacafe.com/watch/650550/ nitric_acid_acts_upon_a_copper_penny_experiment/ http://www.metacafe.com/watch/650550/ nitric_acid_acts_upon_a_copper_penny_experiment/

5. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 5 Indications of a Chemical Reaction Proof: one or more substances has changed identity – chemical change 1.Evolution of energy as heat and/or light 2.Production of a gas 3.Formation of a precipitate 4.Color change

6. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 6 Red, White and Blue Reaction http://www.chem.ox.ac.uk/vrchemistry/FilmStudio/redwhiteblue/page01.htm http://www.chem.ox.ac.uk/vrchemistry/FilmStudio/redwhiteblue/page01.htm

7. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 7 Indications of a Reaction

8. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 8 Characteristics of a Chemical Reaction 1.The equation must contain the correct formulas for the reactants and products. Diatomic elements: I 2 Br 2 Cl 2 F 2 O 2 N 2 H 2 2.The law of conservation of mass must be satisfied. (Mass cannot be created or destroyed) Coefficients – a whole number that appears in front of a formula in a chemical equation.

9. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 9 Diatomic Elements p. 263

10. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 10 Additional Symbols p. 226

11. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 11 Additional Symbols p. 226

12. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 12 Balancing Chemical Equations 1.If the reaction is described by a paragraph, write the word equation. 2.Write the formula for each reactant and product to get the formula equation. 3.Balance the equation.

13. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 13 Balancing Chemical Equations GOAL OF THE GAME: To get the same number of atom of each element in the reactant and the product. To obey the law of conservation of mass.

14. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 14 Balancing Chemical Equations RULES OF THE GAME: Only coefficients can be added or changed. Once formulas are written subscripts can not be changed.

15. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 15 Balancing Chemical Equations TIPS FOR PLAY: Balance the different types of atoms one at a time. First balance elements that appear only once on each side. Balance polyatomic ions that appear on both sides as a single unit. Balance H and O last. page 271

16. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 16 Balancing Chemical Equations TIPS FOR PLAY: Try keeping a tally for each element on each side below the equation. If it could be balanced by a coefficient of 1½ - use it- then multiply all coefficients in the equation by 2.

17. Practice Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 17 ___H 2 + ____N 2 → ____NH 3 ____NaClO 3 → ____NaCl + ____O 2 ___Al 2 (SO 4 ) 3 + ___Ca(OH) 2 → ____Al(OH) 3 + ____CaSO 4 ____C 2 H 6 + ____O 2 → ____CO 2 + ____H 2 O

18. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 18 Sample Problem p.272 The reaction of zinc with aqueous hydrochloric acid produces a solution of zinc chloride and hydrogen gas. Write a balanced equation for the reaction Insert Holt Chemistry Visualizing Matter Disc 1