1 / 25

Chemical Reactions

Chemical Reactions. (Chapter 9 in your textbook!). Chemical Reactions. Chemical Reaction: one substance is converted into a new substance with different chemical and physical properties. Reactants. Products. Chemical Recipes. Think of reactions like chemical recipes. They tell us

maxime
Download Presentation

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. Chemical Reactions (Chapter 9 in your textbook!)

  2. Chemical Reactions • Chemical Reaction: one substance is converted into a new substance with different chemical and physical properties Reactants Products

  3. Chemical Recipes • Think of reactions like chemical recipes. • They tell us • What we start with • How much to use • What you will get • How much you will get • Ingredients = REACTANTS • Cookies = PRODUCTS • EX : Soup recipe • Two cans of condensed soup and four cups of water heated together makes six bowls of soup. 2 cans soup + 4 cups water 6 bowls soup

  4. Yields (makes) + separates reactants from reactants and products from products. (s) solid (l) liquid (g) gas (aq) aqueous Solid product only Gas product only Heat added Catalyst Symbols MnO4

  5. More Chemical Recipes • Example 2 • One package of pasta with eight ounces of sauce can make three plates of spaghetti. 1 pkg pasta(s) + 8 oz sauce(l) 3 plates spag.(s) • Example 3 • Two atoms of solid lithium and one atom of aqueous sulfur combine to form one formula unit of aqueous lithium sulfide. 2Li(s) + S(aq) Li2S(aq)

  6. Pb(ClO4)4 1 Pb, 4 Cl, 16 O V2(CO3)5 2 V, 5 C, 15 O 3 Mn(OH)4 3 Mn, 12 O, 12 H 4 Ca3N2 12 Ca, 8 N 6 Al2(SO3)3 12 Al, 18 S, 54 O Sn(OH)2 1 Sn, 2 O, 2 H Counting Elements

  7. Balancing Chemical Reactions • In any reaction, atoms are conserved. • Rules for Balancing reactions: • 1. Determine correct formulas for reactants and products • 2. Reactants on left Products on right • 3. Count atoms of each element in reactants and products. • 4. Balance the elements one at a time by adjusting only the coefficients. Do not change the subscripts. • 5. Double check each element • 6. Finally, if necessary reduce the coefficients to the lowest ratio.

  8. Balancing Equations The number and type of each element must be the same on both sides of the equation! Fe + O2 Fe3O4 NH3 + H2O  NH4OH Pb(NO3)2 + NaI  PbI2 + NaNO3 H2 + O2 H2O Al + O2 Al2O3

  9. Reaction Types: • Combination (synthesis or addition) A + B → AB Cu + Br2 → • Decomposition CD → C + D ZnO → 3. Single Replacement A + BX → B + AX Fe + CuSO4 →

  10. Reaction Types: (continued) • Double Replacement AB + CD → CB + AD ZnCO3 + CuSO4 → • Combustion Hydrocarbon + O2→ CO2 + H2O C4H8 + O2 →

  11. Synthesis (Combination) Reactions“putting together” • Two single elements or compounds combining to form one compound. • Usually liberate energy • GENERAL FORM : A + B  AB

  12. Al + S Na + Br2 Ca + Cl2 Pb + O2 Mn + F2 Cu + Cl2 S + O2 Synthesis Reaction - Examples

  13. One compound breaking down into two or more atoms or smaller compounds. GENERAL FORM : CD  C + D Most require energy Decomposition Reactions“breaking down”

  14. Decomposition (continued) • Predicting Products • Binary Ionic  Splits in half HgO 

  15. MgS  CaCl2  KI  SrO  PbP  Mn3N4  Decomposition Reaction - Examples

  16. Single Replacement • GENERAL FORM: A + BX  B + AX Please Note : • This will only happen if the metal that is attempting to replace is “stronger” (more reactive) than the metal in the compound Metal reactivity is given on an "Activity Series"

  17. Activity Series Metals on the activity series will replace any metals BELOW them. If not, there will be NO REACTION!

  18. Single Replacement • Replacement of a metal in a compound by a more reactive metal: Mg + CuNO3  Cu + Mg(NO3)2 

  19. Ba + NaCl  Mg + Fe(OH)3  Zn + H2SO4  Pb + AgNO3  Ni + Na2O  Sn + CuSO4  Al + Ag2S  Single Replacement - Examples

  20. Double Replacement • Exchange of positive ions between compounds • Usually in aqueous solutions • Two ionic compounds “switch dancing partners” • GENERAL FORM : AB + CD  CB + AD • Driving Force: • Solid is formed (precipitate) • Gas is produced • Molecular products formed (like H2O)

  21. Double Replacement - Examples • NaCl + AgNO3 • HCl + Na2CO3  • HNO3 + Mg(OH)2  • CuF2 + Na2O  • SrSe + KBr  • NaCl + CaO 

  22. Hydrocarbon Combustion • Hydrocarbon - a compound containing hydrogen and carbon (and sometimes oxygen). • GENERAL FORM : • Hydrocarbon + O2 CO2 +H2O • Steps to balance: • 1. Bal. C, H on the product side, using reactant number. • 2. Count O’s on product side. • 3. Subtract O’s on reactant side, if any. Bal. O’s with oxygen • (sometimes x2)

  23. Hydrocarbon Combustion - Examples C3H8 + O2 C5H12 + O2  C7H16 + O2  C4H10 + O2  C8H18 + O2  C10H22 + O2  CH4 + O2 

  24. H2 + I2 HI  Zn + Pb(NO3)2 Zn(NO3)2 + Pb CsCl + H2S  Cs2S + HCl C3H6 + O2 CO2 + H2O

  25. Mg + Li2S  N.R. Mg + N2 Mg3N2 LiBr  Li + Br2 NH4C2H3O2 + AgNO3 NH4NO3 + AgC2H3O2 Be + O2 BeO C10H22 + O2 H2O + CO2

More Related