1 / 39

Types of Chemical Reactions

Types of Chemical Reactions. Writing Chemical Reactions. Types of Reactions. Many chemical reactions have defining characteristics which allow them to be classified as to type. Types of Chemical Reactions. The five types of chemical reactions in this unit are: Synthesis ( Combination )

elyse
Download Presentation

Types of Chemical Reactions

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Types of Chemical Reactions Writing Chemical Reactions

  2. Types of Reactions • Many chemical reactions have defining characteristics which allow them to be classified as to type.

  3. Types of Chemical Reactions • The five types of chemical reactions in this unit are: • Synthesis ( Combination ) • Decomposition (includes electrolysis) • Single Replacement • Double Replacement • Combustion

  4. Synthesis Reactions • Two or more substances combine to form one substance. • The general form is A + X AX • Example: • Magnesium + oxygen  magnesium oxide • 2Mg + O2 2MgO

  5. Combination Reactions • Combination reactions may also be called composition or synthesis reactions. • Some types of combination reactions: • Combination of elements • K + Cl2 • One product will be formed

  6. Combination Reactions • K + Cl2 • Write the ions: K+ Cl- • Balance the charges: KCl • Balance the equation: 2K + Cl2  2KCl

  7. Combination Reactions • Some types of combination reactions: • Oxide + water  • Nonmetal oxide + water  acid • SO2 + H2O  H2SO3 • Metal oxide + water  base • BaO + H2O  Ba(OH)2

  8. Synthesis (Combination) Reactions • Some types of combination reactions: • Metal oxides + nonmetal oxides • Na2O + CO2 Na2CO3 • CaO + SO2  CaSO3

  9. Decomposition Reactions • One substance reacts to form two or more substances. • The general form is AX  A + X • Example: • Water can be decomposed by electrolysis. • 2H2O  2H2 + O2

  10. Electrolysis of Water

  11. Decomposition Reactions • Types of Decomposition Reactions: • Decomposition of carbonates • When heated, some carbonates break down to form an oxide and carbon dioxide. • CaCO3 CaO + CO2 • H2CO3  H2O + CO2

  12. Decomposition Reactions • Types of decomposition reactions: • Some metal hydroxides decompose into oxides and water when heated. • Ca(OH)2 CaO + H2O Note that this is the reverse of a similar combination reaction.

  13. Decomposition Reactions • Types of decomposition reactions: • Metal chlorates decompose into chlorides and oxygen when heated. • 2KClO3 2KCl + 3O2 • Zn(ClO3)2  ZnCl2 + 3O2 • Some of these reactions are used in explosives.

  14. Decomposition Reactions • Some substances can easily decompose: • Ammonium hydroxide is actually ammonia gas dissolved in water. • NH4OH  NH3 + H2O • Some acids decompose into water and an oxide. • H2SO3 H2O + SO2

  15. Decomposition Reactions • Some decomposition reactions are difficult to predict. • The decomposition of nitrogen triiodide, NI3, is an example of an interesting decomposition reaction.

  16. Nitrogen triiodide

  17. Single Replacement Reactions • A metal will replace a metal ion in a compound. • The general form is A + BX  AX + B • A nonmetal will replace a nonmetal ion in a compound. • The general form is Y + BX  BY + X

  18. Single Replacement Reactions • Examples: • Ni + AgNO3 • Nickel replaces the metallic ion Ag+. • The silver becomes free silver and the nickel becomes the nickel(II) ion. • Ni + AgNO3 Ag + Ni(NO3)2 • Balance the equation: • Ni + 2AgNO3  2Ag + Ni(NO3)

  19. Metal Tree

  20. Single Replacement Reactions • Not all single replacement reactions that can be written actually happen. • The metal must be more active than the metal ion. • Aluminum is more active than iron in Al + Fe2O3 in the following reaction:

  21. Thermite Reaction

  22. Thermite Reaction • Al + Fe2O3 • Aluminum will replace iron(III) as was seen in the video. • Iron(III) becomes Fe and aluminum metal becomes Al3+. • 2Al + Fe2O3 2Fe + Al2O3

  23. Single Replacement Reactions • An active nonmetal can replace a less active nonmetal. • The halogen (F2, Cl2, Br2, I2) reactions are good examples. • F2 is the most active and I2 is the least. • Cl2 +2 NaI  2 NaCl + I2

  24. Double Replacement Reactions • Ions of two compounds exchange places with each other. • The general form is AX + BY  AY + BX • Metathesis is an alternate name for double replacement reactions.

  25. NaOH + CuSO4

  26. Double Replacement • NaOH + CuSO4 • The Na+ and Cu2+ switch places. • Na+ combines with SO42- to form Na2SO4. • Cu2+ combines with OH- to form Cu(OH)2 • NaOH + CuSO4  Na2SO4 + Cu(OH)2 • 2NaOH + CuSO4  Na2SO4 + Cu(OH)2

  27. CuSO4 + Na2CO3

  28. Double Replacement • CuSO4 + Na2CO3 • Cu2+ combines with CO32- to form CuCO3. • Na+ combines with SO42- to form Na2SO4. • CuSO4 + Na2CO3  CuCO3 + Na2SO4

  29. Na2CO3 + HCl

  30. Double Replacement • Na2CO3 + HCl  • Notice that gas bubbles were produced rather than a precipitate. • What was the gas? • Write the double replacement reaction first.

  31. Double Replacement • Na2CO3 + HCl  • Na+ combines with Cl- to form NaCl. • H+ combines with CO32- to form H2CO3. • Na2CO3 + 2HCl  2NaCl + H2CO3 • H2CO3 breaks up into H2O and CO2.

  32. Double Replacement • The gas formed was carbon dioxide. • The final balanced reaction is: Na2CO3 + HCl  NaCl + H2O + CO2. • Balance the equation. • Na2CO3 + 2HCl  2NaCl + H2O + CO2

  33. Combustion Reaction • When a substance combines with oxygen, a combustion reaction results. • The combustion reaction may also be an example of an earlier type such as 2Mg + O2 2MgO. • The combustion reaction may be burning of a fuel.

  34. Combustion Reaction • Methane, CH4, is natural gas. • When hydrocarbon compounds are burned in oxygen, the products are water and carbon dioxide. • CH4 + O2 CO2 + H2O • CH4 + 2O2  CO2 + 2H2O

  35. Combustion Reactions • Combustion reactions involve light and heat energy released. • Natural gas, propane, gasoline, etc. are burned to produce heat energy. • Most of these organic reactions produce water and carbon dioxide.

  36. Practice • Classify each of the following as to type: • H2 + Cl2 2HCl • Combination • Ca + 2H2O  Ca(OH)2 + H2 • Single replacement

  37. Practice • 2CO + O2 2CO2 • Combination and combustion • 2KClO3  2KCl + 3O2 • Decomposition

  38. Practice • FeS + 2HCl  FeCl2 + H2S • Double replacement • Zn + HCl  ? • Single replacement • Zn + 2HCl  ZnCl2 + H2

  39. Types of Chemical Reactions • Read Chapter 8-2 • Review nomenclature • Do all of the practice exercises given in class.

More Related