Chemical Equations and Reactions Mrs. Taylor Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 Demonstration Demonstration Ira Remsen Demo Cu (s) + HNO3 (aq)  CuNO3 (aq) + H2 (g) Chemical Reactions http://www.metacafe.com/watch/650550/ nitric_acid_acts_upon_a_copper_penny_experiment/ Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

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

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

Characteristics of a Chemical Reaction The equation must contain the correct formulas for the reactants and products. Diatomic elements: I2 Br2 Cl2 F2 O2 N2 H2 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. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

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

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

Balancing Chemical Equations RULES OF THE GAME: Only coefficients can be added or changed. Once formulas are written subscripts can not be changed. Balance polyatomic ions that appear on both sides as a single unit. Balance H and O last. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 Practice ___H2 + ____N2 → ____NH3 ____NaClO3 → ____NaCl + ____O2 ___Al2(SO4)3 + ___Ca(OH)2 → ____Al(OH)3 + ____CaSO4 ____C2H6 + ____O2 → ____CO2 + ____H2O Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

BALANCE THE EQUATIONS ____Al + ____N2 → ____AlN   ____Fe + ____O2 → ____Fe3O4 ____ZnS + ____O2 → ____ZnO + ____SO2 ____Na + ____H2O → ____H2 + ____NaOH Chapter 8 Section 1 Describing Chemical Reactions p. 261-275