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Modern Chemistry Chapter 8 Chemical Equations and Reactions

Modern Chemistry Chapter 8 Chemical Equations and Reactions. Sections 1, 2 & 3 Describing Chemical Reactions Types of Chemical Reactions Activity Series of the Elements. Chapter Vocabulary. chemical equation precipitate coefficient formula equation reversible reaction. Section 1.

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Modern Chemistry Chapter 8 Chemical Equations and Reactions

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  1. Modern ChemistryChapter 8Chemical Equations and Reactions Sections 1, 2 & 3 Describing Chemical Reactions Types of Chemical Reactions Activity Series of the Elements Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  2. Chapter Vocabulary chemical equation precipitate coefficient formula equation reversible reaction Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

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

  5. Oh, That Curious Ira Remsen! This demonstration has its roots in the writings of Ira Remsen, a 19th century professor of chemistry at Johns Hopkins University. In his memoir, Remsen writes.... "While reading a textbook of chemistry I came upon the statement, nitric acid acts upon copper. I was getting tired of reading such absurd stuff and I was determined to see what this meant. Copper was a more or less familiar to me, for copper cents were then in use. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  6. Oh, That Curious Ira Remsen! "I had seen a bottle marked nitric acid on a table in the doctor's office where I was then doing time. I did not know its peculiarities, but the spirit of adventure was upon me. Having nitric acid and copper, I had only to learn what the words acts upon meant . The statement nitric acid acts upon copper would be something more than mere words. All was still. In the interest of knowledge I was even willing to sacrifice one of the few copper cents then in my possession. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  7. Oh, That Curious Ira Remsen! "I put one of them on the table, opened the bottle marked nitric acid, poured some of the liquid on the copper and prepared to make an observation. But what was this wonderful thing which I beheld? The cent was already changed and it was no small change either. A green-blue liquid foamed and fumed over the cent and over the table. The air in the neighborhood of the performance became colored dark red. A great colored cloud arose. This was disagreeable and suffocating. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  8. Oh, That Curious Ira Remsen! "How should I stop this? I tried to get rid of the objectionable mess by picking it up and throwing it out of the window. I learned another fact. Nitric acid not only acts upon copper, but it acts upon fingers. The pain led to another unpremeditated experiment. I drew my fingers across my trousers and another fact was discovered. Nitric acid acts upon trousers. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  9. Oh, That Curious Ira Remsen! " Taking everything into consideration, this was the most impressive experiment and relatively probably the most costly experiment I have ever performed... It was a revelation to me. It resulted in a desire on my part to learn more about that remarkable kind of action. Plainly, the only way to learn more about it was to see its results, to experiment, to work in a laboratory." Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

  11. 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

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

  13. Ammonium Dichromate Volcano SeeAmmonium Dichromate Volcano on Houghton Mifflin Chemistry DVD p. 261 Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

  15. Characteristics of a Chemical Reaction • The equation must represent know facts. • The equation must contain the correct formulas for the reactants and products. • Diatomic elements: I2 Br2 Cl2 F2 O2 N2 H2 • Molecular elements: S8 P4 (page 263) • The law of conservation of mass must be satisfied. • 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

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

  17. Word and Formula Equations • Word equations – reactants & products expressed in words methane + oxygen  carbon dioxide + water PRODUCTS REACTANTS YIELDS Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  18. Word and Formula Equations • Formula equations – reactants & products expressed with formulas – not balanced methane + oxygen  carbon dioxide + water CH4 (g) + O2 (g)  CO2(g) + H2O(g) STATE OF MATTER SYMBOLS Solid (s)Liquid (l) Gas (g)Aqueous (aq)  Dissolved in water Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  19. Methane Combustion p. 265 Insert Glencoe Chemistry Concepts & Applications Disc 1 Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  20. Additional Symbols MnO2 CATALYST ELECTROLYSISSPECIFIC TEMPSPECIFIC PRESSURE YIELDS REVERSIBLE PRECIPITATE GAS REACTANTSHEATED e- 0°C  2 atm heat TABLE ON PAGE 226 Chapter 8 Section 1 Describing Chemical Reactions p. 261-275 p. 226

  21. p. 270 Electrolysis Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

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

  24. p.266 Chemical Equations Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  25. Balancing Chemical Equations • If the reaction is described by a paragraph, write the word equation. • Write the formula for each reactant and product to get the formula equation. • Balance the equation. • Insert state of matter symbols and other additional symbols. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

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

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

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

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

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

  32. 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

  33. H H Cl Cl Cl Zn Cl H H Sample Problem p.272 Zn + HCl  ZnCl2 + H2 2 zinc + hydrochloric acid  zinc chloride + hydrogen Zn Zn (s) + 2HCl (aq) ZnCl2 (aq) + H2 (g) Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  34. Sample Problem p.273 Solid aluminum carbide, reacts with water to produce methane gas, CH4, and solid aluminum hydroxide. Write a balanced chemical equation for this reaction. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  35. Sample Problem p.273 Al4C3 + H2O CH4 + Al(OH)3 12 3 4 aluminum carbide + water  methane + aluminum hydroxide Al = C = H = O = 4 3 2 1 4 3 24 12 Al = C = H = O = 1 1 7 3 4 1 16 12 4 3 24 12 Al4C3(s) + 12H2O (l) 3CH4 (g) + 4Al(OH)3 (s) Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  36. Sample Problem p.273 Aluminum sulfate and calcium hydroxide are used in water-purification process. When added to water, they dissolve and react to produce two insoluble products, aluminum hydroxide and calcium sulfate. These products settle out, taking suspended solid impurities with them. Write a balanced chemical equation for the reaction. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  37. Sample Problem p.273 Al2(SO4 )3 + Ca(OH)2  Al(OH)3 + CaSO4 3 2 3 aluminum sulfate + calcium hydroxide  aluminum hydroxide + calcium sulfate Al = SO4 = Ca = OH = 2 3 1 2 2 3 3 6 Al = SO4 = Ca = OH = 2 1 1 6 1 1 1 3 2 3 3 6 Al2(SO4)3(aq) + 3Ca(OH)2(aq) 2Al(OH)3(s) + 3CaSO4(s) Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

  39. Practice Problems page 272 • Write word, formula, and balanced chemical equations for each of the following reactions: • Magnesium and hydrochloric acid react to produc magnesium chloride and hydrogen. • Aqueous nitric acid reacts with solid magnesium hydroxide to produce aqueous magnesium nitrate and water Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  40. Practice Problems page 272 2. Solid calcium metal reacts with water to form aqueous calcium hydroxide and hydrogen gas. Write a balanced chemical equation for this reaction. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  41. Practice Problems page 272 • Write balanced chemical equations for each of the following reactions: • Solid sodium combines with chlorine gas to produce solid sodium chloride. • When solid copper reacts with aqueous silver nitrate, the products are aqueous copper (II) nitrate and solid silver • In a blast furnace, the reaction between solid iron (III) oxide and carbon monoxide gas produces solid iron and carbon dioxide gas. Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  42. Coefficients in a Equzation Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  43. Significance of a Equation 4 Fe (s) + 3O2(g)  2Fe2O3(s) Coefficients = molecules (or formula units for ionic or atoms for elements) 4 ATOMS 3 MOLECULES 2 FORMULA UNITS 4 MOLES 3 MOLES 2 MOLES 223.4g 96.00 g 319.40g + = Convert moles to grams 4mol Fe x 55.85g/1mole = 223.4g Coefficients = moles Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

  44. Interpreting Chemical Equations p.269 Chapter 8 Section 1 Describing Chemical Reactions p. 261-275

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

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