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Friday March 7 th , 2014

Friday March 7 th , 2014. You need: notes notebook, pen/pencil Please turn in your percent comp quiz corrections (if you have not already) QOTD- What was Dalton’s theory about reactions? (you might need to look into your notes). Housekeeping.

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Friday March 7 th , 2014

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  1. Friday March 7th, 2014 You need: notes notebook, pen/pencil Please turn in your percent comp quiz corrections (if you have not already) QOTD- What was Dalton’s theory about reactions? (you might need to look into your notes).

  2. Housekeeping • HW DUE MONDAY- 5 dimensional analysis problems (from wksht) AND 10 problems from balancing equations worksheet.

  3. Chemical Reactions

  4. Reactions and Equations • According to Dalton's atomic theory: A chemical reaction occurs when atoms are combined, separated, and/or rearranged. The atoms themselves are not created or destroyed, nor are they changed into different elements. He proposed this in 1803, and it still stands today.

  5. Reactions and Equations There are several ways to represent a reaction: a. Word equations, b. skeleton equations (element symbols and states), c. chemical equations. • A balanced chemical equation shows that everything you started with in a chemical reaction is still there after the reaction is over.

  6. Writing balanced chemical equations: 1. Write a skeleton equation, which shows what the products and reactants are without any concern for the amounts of each. Example: Aluminum reacts with oxygen to form aluminum oxide. The skeleton equation is: Al + O2 ---> Al2O3 Symbols: + means "together with" ---> means "makes, produces“ Vocabulary: The materials you start with are the reactants, and they are shown on the left side of the equation. The materials that are formed are the products, and they are shown on the right side.

  7. 2. Adjust the relative amounts of each reactant and product by inserting whole numbers before the formulas. These numbers are called coefficients. A coefficient must be a whole number, and it is distributed to every element in the compound. Example: Al + O2 ---> Al2O3 The 2 in front of the Al2O3 means that, altogether, you finished with four pieces of aluminum and six pieces of oxygen, which matches the left side of the equation.

  8. There is no one way to balance a chemical equation. It pretty much boils down to trial and error, and that takes practice. One more thing ... What's wrong with this chemical equation? 2 C2H4 + 6 O2 ---> 4 CO2 + 4 H2O The coefficients must be as low as possible, and it is a common mistake to end up with coefficients that are higher than they have to be. These coefficients can all be divided by two.

  9. Monday March 10th, 2014 You need: Notes notebook, pen/pencil and DA worksheet as well as Balancing equations worksheet. QOTD: Balance the following equations Na3PO4 + KOH  NaOH + K3PO4 MgF2 + Li2CO3 MgCO3 + LiF P4 + O2 P2O3 RbNO3 + BeF2 Be(NO3)2 + RbF

  10. Housekeeping • HW tonight (DUE 3/11/14) • Complete 5 problems from your dimensional analysis worksheet • Read over chapter 8 (specifically 8.1 and 8.2) Quiz on balancing equations- Monday March 17th, 2014 Be prepared for lab this Friday (Pants!!!!!!) ****if you are struggling come and get help!

  11. Types of Reactions • There are five types of chemical reactions we will talk about: • Synthesis reactions • Decomposition reactions • Single displacement reactions • Double displacement reactions • Combustion reactions • You need to be able to identify the type of reaction and predict the product(s)

  12. Steps to Writing Reactions • Some steps for doing reactions • Identify the type of reaction (by the types of reactants) • Predict the product(s) using the type of reaction as a model • Balance it Don’t forget about the diatomic elements! (BrINClHOF) For example, Oxygen is O2 as anelement. In a compound, it can’t be a diatomic element because it’s not an element anymore, it’s a compound!

  13. 1. Synthesis reactions • Synthesis reactions occur when two substances (generallyelements) combine and form a compound. (Sometimes these are called combination or addition reactions.) reactant + reactant  1 product • Basically: A + B  AB • Example: 2H2 + O2  2H2O • Example: C+ O2  CO2

  14. Synthesis Reactions • Here is another example of a synthesis reaction

  15. Tuesday March 11th, 2014 You need: notes notebook, pen/pencil and DA wksht problems (6-10) QOTD Predict the products. Write and balance the following synthesis reaction equations. • Sodium metal reacts with chlorine gas • Solid Magnesium reacts with fluorine gas • Aluminum metal reacts with fluorine gas

  16. Housekeeping • HW tonight #’s 11-15 on balancing equations wksht • Tomorrow you need BOTH worksheets in class! • QUIZ on balancing reactions next Monday 3/17 • Lab next Monday (pants)- 3/17

  17. 2. Decomposition Reactions • Decomposition reactions occur when a compound breaks up into the elements or in a few to simpler compounds • 1 Reactant  Product + Product • In general: AB  A + B • Example: 2 H2O  2H2 + O2 • Example: 2 HgO  2Hg + O2

  18. Decomposition Reactions • Another view of a decomposition reaction:

  19. Decomposition Exceptions • Carbonates and chlorates are special case decomposition reactions that do not go to the elements. • Carbonates (CO32-) decompose to carbon dioxide and a metal oxide • Example: CaCO3  CO2 + CaO • Chlorates (ClO3-) decompose to oxygen gas and a metal chloride • Example: 2 Al(ClO3)3  2 AlCl3 + 9 O2 • Hydroxides (OH-) decompose to H2O and a metal oxide • Example: Ca(OH)2  CaO + H2O

  20. Practice • Predict the products. Then, write and balance the following decomposition reaction equations: • Solid Lead (IV) oxide decomposes PbO2(s)  • Aluminum nitride decomposes AlN(s) 

  21. Wed/Thurs March 12th/13th, 2014 You need: Notes notebook pen/pencil, balancing equations wksht out to be checked for credit QOTD Identify the type of reaction for each of the following synthesis or decomposition reactions, and write the balanced equation: N2(g) + O2(g) BaCO3(s)  Co(s)+ S(s)  NI3(s) 

  22. Housekeeping HW tonight (3/14) DUE mon 3/17 • Pre-lab for “chemical dropouts”- on website • Finish balancing chemical equations worksheet, dimensional analysis (front side) and second balancing worksheet 3/17 QUIZ on balancing chemical equations (10 points) 3/21 QUIZ –Dimensional analysis/stoichiometry

  23. Today (5th and 7th period) Your job (with your dot partner): 1. Finish balancing equations worksheet #1 and worksheet #2 (handed out today) • Work toghether • Help your partner; make sure they understand what is happening • Check balancing by checking starting/ending mass (I’ll show you how) 2. When instructed; new groups will form and work on dimensional analysis homework (front side of worksheet)

  24. Monday March 17th, 2014 You need: notes notebook, pen/pencil, balancing equations worksheet (2) and dimensional analysis worksheet. Sit quietly…. You have a quiz 

  25. Housekeeping 1. HW- tonight: • First 5 problems from the back of dimensional analysis worksheet • PRINT out statue of liberty article from website AND statue of liberty questions doc- Read article • Answer questions by Monday (3/24) 2. Lab will be moved to next week 3. Quiz- dimensional analysis on Friday March 21st, 2014

  26. Agenda • Balancing quiz • Housekeeping • Review balancing equations worksheets • Review remainder of dimensional analysis worksheet • Lecture notes (if time)

  27. Tues, Wed, Thurs March 18th, 19th, 20th2014 You need: Notes notebook, pen/pencil Turn in Dimensional analysis worksheet on the demonstration desk. Make sure your name is on it! QOTD (Put the following reactions into skeleton form…don’t forget to balance) 1. calcium + oxygen 2. copper + sulfur copper(II) sulfide 3. calcium oxide + water calcium hydroxide 4. hydrogen + nitrogen

  28. Housekeeping HW (Due Monday March 24th) • Identification of reactions worksheet (if lecture gets finished) 2. PRINT out statue of liberty article from website AND statue of liberty questions doc- Read article Answer questions by Monday (3/24) OTHER: • QUIZ FRIDAY (3/21)- dimensional analysis (10 problems)

  29. AGENDA • QOTD • Housekeeping • Lecture notes • Homework practice (together if time)

  30. 3. Single Replacement Reactions • Single Replacement Reactions occur when one element replaces another in a compound. • A metal can replace a metal (+) OR a nonmetal can replace a nonmetal (-). • element + compound product + product A + BC  AC + B (if A is a metal)OR A + BC  BA + C (if A is a nonmetal) (remember the cation always goes first!) When H2O splits into ions, it splits into H+ and OH- (not H+ and O-2 !!)

  31. Single Replacement Reactions • Another view:

  32. Single Replacement Reactions • Write and balance the following single replacement reaction equation: • Zinc metal reacts with aqueous hydrochloric acid Zn(s) + HCl(aq) ZnCl2 + H2(g) Note: Zinc replaces the hydrogen ion in the reaction 2

  33. Single Replacement Reactions • Sodium chloride solid reacts with fluorine gas NaCl(s) + F2(g)  NaF(s) + Cl2(g) Note that fluorine replaces chlorine in the compound • Aluminum metal reacts with aqueous copper (II) nitrate 2Al(s)+ 3Cu(NO3)2(aq) 2Al(NO3)3(aq) + 3Cu(s) 2 2

  34. 4. Double Replacement Reactions • Double Replacement Reactions occur when a metal replaces a metal in a compound and a nonmetal replaces a nonmetal in a compound • Compound + compound  product + product • AB + CD  AD + CB

  35. Double Replacement Reactions • Think about it like “foil”ing in algebra, first and last ions go together + inside ions go together Example: AgNO3(aq) + NaCl(s)  AgCl(s) + NaNO3(aq) Another example: K2SO4(aq) + Ba(NO3)2(aq)  KNO3(aq) + BaSO4(s)

  36. Practice • Predict the products. Balance the equation • HCl(aq) + AgNO3(aq)  • CaCl2(aq) + Na3PO4(aq)  • Pb(NO3)2(aq) + BaCl2(aq)  • FeCl3(aq) + NaOH(aq)  • H2SO4(aq) + NaOH(aq)  • KOH(aq) + CuSO4(aq) 

  37. Friday March 21st, 2014 You need: Notes notebook, pen/pencil QOTD Summarize in your own words a single displacement reaction and double displacement reactions, this should be in sentence form. When you are finished discuss your answer with your dot partner

  38. Housekeeping Dimensional analysis quiz is MOVED to TUES March 25th, 2014. HW- DUE Monday- statue of liberty article questions (website) DUE Monday- Reaction Type prediction worksheet (you will get it today)

  39. Agenda • Combustion reactions • Reaction prediction worksheet

  40. 5. Combustion Reactions • Combustion reactions occur when a hydrocarbon reacts with oxygen gas. • This is also called burning!!! In order to burn something you need the 3 things in the “fire triangle”:1) A Fuel (hydrocarbon)2) Oxygen to burn it with3) Something to ignite the reaction (spark)

  41. Combustion Reactions • In general: CxHy + O2  CO2 + H2O • Products in combustion are ALWAYS carbon dioxide and water. (although incomplete burning does cause some by-products like carbon monoxide) • Combustion is used to heat homes and run automobiles (octane, as in gasoline, is C8H18)

  42. Combustion Reactions Edgar Allen Poe’s drooping eyes and mouth are potential signs of CO poisoning.

  43. Combustion • Example • C5H12 + O2 CO2 + H2O • Write the products and balance the following combustion reaction: • C10H22 + O2  8 6 5

  44. Monday March 24th, 2014 You need: notes notebook, pen/pencil HW out to be checked for credit: 1. Chemical dropouts pre-lab, 2. statue of liberty article questions QOTD State the type, predict the products, and balance the following reactions: • BaCl2 + H2SO4 • C6H12 + O2  • Zn + CuSO4  • Cs + Br2  • FeCO3 

  45. Agenda • QOTD/HW check • Housekeeping • Exam discussion • Review notes from last week

  46. Housekeeping NO HW tonight 3/25 quiz dimensional analysis 4/1 Reactions Exam (scoring guide handed out tomorrow) LAB wed/thurs (3/26 and 3/27) PANTS!!!!!!!!!!

  47. Tuesday March 25th, 2014 You need: • Notes notebook • pen/pencil • Calculator • balancing/predicting reactions worksheet out to be checked for credit Reminder- you have a quiz today 

  48. Housekeeping • HW: Finish Reaction words to skeleton worksheet and/or Can we speak chem yet? • LAB WED/THURS (PANTS!!!!!!) • Exam Tuesday April 1st, 2014 • You will receive your scoring guide Friday March 28th, 2014

  49. Agenda • Partner quiz/HW check off • Review balancing/predicting worksheet • Review statue of liberty article questions • Reaction words to skeleton form (previous worksheet) • Can we speak Chemistry yet? • Start Net Ionic Equations

  50. Wed/Thurs March 26th/27th You need: Notes notebook, Chemical dropouts pre-lab, Word equation worksheet. Agenda: • pre-lab notes • Lab/practice rotation (word to skeleton equations) • Net ionic equations • Statue of liberty article review

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