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Supplemental packet page 117

Supplemental packet page 117. reactants. This is a chemical recipe for the decomposition of water by electrolysis. products. What did John Dalton in 1808 have to say about chemical reactions?. 1. Chemical reactions involve just the simple rearrangement of atoms.

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Supplemental packet page 117

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  1. Supplemental packet page 117

  2. reactants This is a chemical recipe for the decomposition of water by electrolysis. products What did John Dalton in 1808 have to say about chemical reactions? 1. Chemical reactions involve just the simple rearrangement of atoms. 2. Atoms are conserved in a chemical reaction. In other words, atoms are not created nor destroyed in chemical reaction.

  3. Write the following opposite supplemental packet page 106 Is this true for the decomposition of water by electrolysis?

  4. 1. Chemical reactions involve just the simple rearrangement of atoms. 2. Atoms are conserved in a chemical reaction. In other words, atoms are not created nor destroyed in chemical reaction. This ture for the below decomposition of water by electrolysis. 4 hydrogen atoms 4 hydrogen atoms 2 oxygen atoms 2 oxygen atoms Let’s see if John Dalton had assumed correctly.

  5. Stoichiometry supplemental packet page 117 36 grams H2O produces 4 grams H2 and 32 grams O2

  6. Stoichiometry supplemental packet page 118

  7. 0 0 (l) Reduction is Gain, RIG (g) (g) 2H+ + 2e- H20 The battery supplies those electrons Remember hydrogen ions’s favorite charge in its combined state is: H+

  8. 0 0 2- (l) (g) (g) Oxidation is loss of electrons, OIL So oxide ion must have lost electrons O2- O0 + 2e- Remember oxygen ion’s favorite charge in its combined state is: O2- Lost electrons in the electrolysis are attracted To the positive ca hode Then what happened the oxygen atom in water?

  9. 0 0 (l) (g) (g) 2H+ + 2e- H20 O2- O0 + 2e- Take the summation of both half-reactions affords the overall rxn below REDOX, is about the exchange of electrons. Summary: Reduction is Gain, RIG Oxidation is Loss, OIL

  10. Supplemental packet page 106 Equilibrium off-balanced (unequal) Just Shot Me gas formation reactant to product Equilibrium balance Up & Down Reflux like acid reflux (heart burn) Precipitation saturation (solid formation)

  11. Supplemental packet page 106

  12. Supplemental packet page 106 Don’t do this!!!!

  13. Write this into our notes In balancing, we would like the lowest whole number molar ratio. Where the number out in front is called a molar coefficient. 2 1 2

  14. 1 2 2 • 1 2 • 1 The reaction is balanced, BUT there is a fractional molar coefficient. We must remove the fraction by multiplying through by 2. 2 1 2 1 2 2 • 2 • But what if an individual balanced the magnesium first? 1 1 In my opinion, the following is the easiest way to balance, if you: 1) always balance oxygens last; 2) then multiply by factor of 2, to remove any fractional molar coefficient that might be present in the balanced reaction.

  15. 3 3 2 2 2 • 2 2 • 1 4 3 2 2 • 2 • 2 1 Note: We are going for the lowest whole number Molar coefficient ratio

  16. (s) (s) (s) (g) 4 3 2 magnesium metal solid iron metal solid oxygen gas magnesium oxide solid ionic salt (g) (s) oxygen gas iron (III) oxide solid TM ionic salt Finally, name the compounds and give physical states.

  17. ? 2 Combustion of methane gas 1 2 1 1 • O2 + 2 • 1O Always balance oxygens last ? • O2 = 4 2 + 2 = 4

  18. 7 2 ? 7 3 2 2 2 • 1 2 • 3 2 • 2 2 7 6 4 2 • Combustion of ethane gas 1 2 2 • O2 + 3 • 1O Always balance oxygens last ? • O2 = 7 4 + 3 = 7

  19. ? 2 1 + ? • 2 = 4 Now solve for “?” Substract one from each side -1 -1 ? • 2 = 3 2 2 Divide each side by 2 ? = 3 3 2 2 Combustion of methanol liquid 1 1 1 • O2 + 2 • 1O Always balance oxygens last 1 • O + ? • O2 = 4 2 + 2 = 4

  20. 3 2 ? 2 2 2 x 1 2 x 1 2 x 2 2 3 4 2 2 x 3 2 Combustion of methanol liquid 1 1

  21. ? 6 Now solve for “?” 6+ ? • 2 = 18 2 2 -6 -6 ? • 2 = 12 Divide each side by 2 ? = 6 Now balance the combustion of glucose (blood sugar) 1 6 6 1 • O2 + 6 • 1O Always balance oxygens last 12 + 6 = 18 1•O6 + ? • O2 = 18 Substract 6 from each side

  22. chlorophyll catalyst CO2 + H2O C6H12O6 + O2 Combination - Synthesis - PHOTOSYNTHESIS 6 6 1 6

  23. CH4O + O2 CO2 + H2O CH4O + O2 CO2 + H2O 2x C2H6O + O2 CO2 + H2O 2 2 4 3 CH2O + O2 CO2 + H2O C 4+ O2– O2– Combustion of methanol, CH4O Don’t leave as a fraction, multiply through by 2 combustion 3 __ 2 1 1 2 Combustion of ethanol, C2H4O 1 3 2 3 Combustion of formaldehyde, CH2O 1 1 1 1 What reactant was oxidized? What reactant was reduced?

  24. A+B- (aq) + C+D- (aq) AD(?) + BC(?) you’ll need to determine state based on some rules Ionic salt transfer reactions in aqueous solution Ionic salt solubility in water All group I salts soluble, Li,Na,K All nitrate salts soluble All ammonium salts soluble,NH4+ Driving forces for ion transfer, a force that makes the reaction go. Physical state formations: If a solid forms If a liquid forms If a gas forms Evidence for chemical change, ∆ Color change (tricky) Heat evolved (tricky) precipitation saturation (solids) If a liquid forms (heat evolved) If a gas forms (bubbles, odor)

  25. A+B- (aq) + C+D- (aq) AD(?) + BC(?) Use of common sense tells us that, An acids mixed with a base (antacid) causes a neutralization. H+A- (aq) + M+OH- (aq) H2O (l) + MA(?) Use of common sense tells us that, An acids mixed with carbonate (HCO3-) produces CO2 water and salt H+A- (aq) + NaHCO3(aq) H2O(l) + NaA(aq) CO2 (g) Ionic salt transfer reactions in aqueous solution Common sense tells us to mix ionic solutions in order to have an reaction to occur. (we are not going to mix for the sake of mixing)

  26. A+B- (aq) + C+D- (aq) AD(?) + BC(?) Say the product names Now write the ions associated with each substance Ag+ (NO3)– Na+ Cl- Ag+ Cl- Na+ (NO3)– Now write formuals for the products Identify physical state in aqueous solution Solubility rules need to be applied. AgCl + NaNO3 (s) (aq)

  27. carbide ion phosphide ion phosphate ion borate ion nitride ion sulfide ion sulfate ion carbonate ion oxide ion chloride ion perchlorate ion nitrate ion fluoride X- charges

  28. iron metal chlorine gas forms> iron (II) chloride plus 1 1 Oxidation OIL Reduction RIG Fe(s) + Cl2(g) FeCl2 (s) Cl2o + 2e- 2Cl – Feo Fe 2+ + 2e- Fe 2+ Cl – Cl – Combination - Synthesis (the REDOX process defined) 1 1 1 Analyzing the half reactions

  29. Combination - Synthesis (the REDOX process defined) iron metal chlorine gas forms iron (II) chloride 1 1 1 Analyzing the half reactions Oxidation OIL Reduction RIG Cl2o + 2e- 2Cl – Feo Fe 2+ + 2e- Fe(s) + Cl2(g) FeCl2 (s) the electrons on the reactant side cancel the electrons on the product side Fe 2+ Cl – Cl – 1 1 1 1 combining both half reactions 1 Fe(s) + 1 Cl2(g) 1 FeCl2 (s)

  30. Mgo lost electrons (s) (s) (g) magnesium metal solid oxygen gas magnesium oxide solid ionic salt Oxygen gained electrons Mg O Mg 2+ O2O O2– What reactant was oxidized? What reactant was reduced?

  31. Iron metal lost electrons (s) 4 3 2 iron metal solid (g) (s) oxygen gas iron (III) oxide solid TM ionic salt Oxygen gained electrons Fe 3+ Fe 3+ Fe O O2– O2– O2– O2O What reactant was oxidized? What reactant was reduced?

  32. Fe + Cl2 FeCl2 4 hydrogen atoms 4 hydrogen atoms 2 oxygen atoms 2 oxygen atoms Combustion of methanol in PLASTIC BOTTLE REDOX MID-TERM 1 1 1

  33. BATTERY DEMO SOLUBILITY in aqueous solutions

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