Chemical Equations & Reactions.

Transcription

1 Chemcal Equaton & Reacton

2 Sgn of Chemcal Reacton There are fve man gn that ndcate a chemcal reacton ha taken place: releae change n color change n odor producton of new gae or vapor n p u t nput or releae of energy/heat formaton Irreverble Sold formaton (precptate)

3 Chemcal Reacton are repreented by equaton Chemcal equaton They have to be balanced Predct product from reactant Type of Chemcal equaton Synthe Decompoton Sngle replacement Double replacement Combuton

4 Type of Chemcal Reacton A B AB Synthe (Combnaton) rxn AB A B Decompoton (breakng apart) rxn Sngle-replacement rxn Double-replacement rxn Neutralzaton rxn Combuton rxn (of a hydrocarbon) Polymerzaton A BC AC B element compound compound element AB CD AD CB compound compound compound compound HX BOH BX HOH acd bae alt water CH O2 CO2 H2O Polymer = monomer monomer

5 Synthe Reacton Drect combnaton two or more element (Synthe) 2 Na Cl2 Na Cl Na Cl General form: A element or Compound B element or compound 2 NaCl Na Cl - Cl Na - AB compound

6 Synthe Reacton Example Photoynthe 6 CO2 6 H2O O2 C6H12O6 Formaton of water 2 H2 O 2 H 2O Formaton of alt 2 Na Cl2 2 2 NaCl General Form A B C 6

7 Decompoton Reacton Decompoton reacton breakng of a molecule or a compound. 2 H2O O H O H 2 H2 HH H General form: AB compound H2 O2 O B O H2 A two or more element or compound

8 Decompoton Reacton Example Hydrogen Peroxde 2 H 2O 2 O2 2 H 2O 2 H2 Electroly of water 2 H 2O electrcty Ntrogen trodde 2 NI3 I2 General Form AB N2 3 A B O2

9 Sngle and Double Replacement Reacton Sngle-replacement reacton Mg CuSO4 General form: A BC MgSO4 AC Cu B Double-replacement reacton CaCO3 H2CO3 General form: AB 2 HCl CaCl2 CD AD CB

10 Sngle-Replacement Reacton Magc blue-earth Fe CuCl2 FeCl2 Cu Znc n ntrc acd Zn H2 2 HNO3 Zn(NO 3)2 General Form A BC AC B

11 Double Replacement Reacton K2CO3 () Potaum carbonate BaCl2 () Barum chlorde 2 KCl () Potaum chlorde BaCO3 () Barum carbonate

12 Formaton of a old: AgCl AgNO3() KCl() KNO3 () AgCl()

13 Combuton Reacton Combuton alway nvolve Oxygen and produce Carbon Doxde and Water.

14 Wrte a balanced chemcal equaton for the followng combuton reacton: A. 8 O2 H 2O 5 CO2 B. 2 C22H46 67 O2 H 2O 44 CO2 46 C15H28 22 O2 H 2O 15 CO2 14 C. C5H12 6

15 Chemcal Equaton alumnum oxde Depct the knd of reactant and product product and ther relatve amount n a reacton. Reactant Product 4 Al() 3 O2(g) 2 Al2O3() The letter (), (g), () and (l) are the phycal tate of compound. The number n the front are called tochometrc coeffcent.

16 Chemcal Equaton 4 Al() 3 O2(g) Al2O3() 2 alumnum oxde andpaper 4 g Al 3 g O2 yeld 2 g Al2O3 Th equaton mean: 4 Al mole 3 O2 mole yeld 2 mole of Al2O3 108 g 4 mol Al@27g/mol 96 g 3 mol O2@32g/mol = 204 g 2 mol Al2O3@102g/mol

17 Chemcal Equaton A reacton begn wth ame amount of reactant and end wth the ame amount of product n a ytem (doe not change. Atom Only get rearranged. 100% Kotz web Chemca l Factory 100% 20% 80%

18 Word Equaton Wrte the word equaton for the reacton of methane ga wth oxygen ga to form carbon doxde and water. methane oxygen Reactant CH4 2 O2 carbon doxde water Product CO2 2 H 2O

19 Vualzng a Chemcal Reacton 2 Na 10 mole Na Cl2 5 mole Cl2 2 NaCl 10? mole NaCl

20 Vualzng a Chemcal Reacton 2 Na Cl2 2 NaCl

21 Meanng of Chemcal Formula Chemcal Symbol H2O Meanng One molecule of water: Compoton Two H atom and one O atom 2 H2O Two molecule of water: Four H atom and two O atom H2O2 One molecule of hydrogen peroxde: Two H atom and two O atom

22 Balancng Chemcal Equaton Balanced Equaton one n whch the number of atom of each element a a reactant equal to the number of atom of that element a a product Determne whether the followng equaton balanced. 2 Na H2O 2 NaOH H2 2 Na 2 H2O 2 NaOH H2

23 Balancng Chemcal Equaton Other example NO(g) O2(g) NO2(g) t balanced? I th balanced? NO(g) O(g) NO2(g) I th OK? I th balanced? NO(g) ½ O2(g) NO2(g) I th OK?

24 Balancng Chemcal Equaton An mportant pont to remember 2 NO(g) O2(g) 2NO2(g) Coeffcent are multpler for every atom n the molecule. The ubcrpt n O2(g) and NO2(g) refer to the number of atom of th type that are preent n each molecule

25 NEVER CHANGE OR MANIPULATE THE SUBSCRIPTS 2 NO(g) O2(g) 2NO2(g) Subcrpt

26 CH4 2 O2 CO2 2 H2O Reactant 1 C atom 4 H atom 4 O atom Product 1 C atom 4 H atom 4 O atom

27 Wrte the balanced equaton for the reacton between alumnum ulfate and calcum chlorde to form a whte precptate of calcum ulfate. 1) Wrte a word equaton for the reacton.?? alumnum ulfate calcum chlorde calcum ulfate alumnum chlorde 2) Wrte the correct formula for all reactant and product. Al2(SO4)3 AlCl3 CaCl2 CaSO4 3) Determne the coeffcent that make the equaton balance. Al2(SO4)3 AlCl3 3 CaCl2 3 CaSO4 2

28 Wrte a balanced equaton for the reacton between chlorne and odum bromde to produce bromne and odum chlorde. 1) Wrte a word equaton for the reacton. chlorne odum bromde bromne odum chlorde 2) Wrte the correct formula for all reactant and product. Cl2 NaBr Br2 NaCl 3) Determne the coeffcent that make the equaton balance. Cl2 2 NaBr Br2 2 NaCl

29 Addtonal Symbol Ued n Chemcal Equaton Yeld ; ndcate reult of reacton Ued to ndcate a reverble reacton () A reactant or product n the old tate; alo ued to ndcate a precptate Alternatve to (), but ued only to ndcate a precptate (l) () (g) A reactant or product n the lqud tate A reactant or product n an ueou oluton (dolved n water) A reactant or product n the gaeou tate

30 Solublty Ionc Equaton Cover the anwer, work the problem, then check the anwer. 1. Dolve ammonum ntrate: 2. Precptate cuprc hydroxde: 3. Dolve chromum thocyanate: 4. Precptate lead arenate: NH4NO3 () ---> NH41 () NO3-1 () Cu2 () 2OH-1 () ---> Cu(OH)2 () Cr(SCN)3 () ---> Cr3 () 3SCN-1 () 3Pb2 () 2AO4-3 () ---> Pb3(AO4)2 () 5. Dolve lcon permanganate: S(MnO4)4 () ---> S4 () 4MnO4-1 () 6. Precptate znc phophate: 3Zn2 () 2PO4-3 () ---> Zn3(PO4)2 ()

31 acetate bromde carbonate chlorde chromate hydroxde odde ntrate phophate ulfate ulfde TABLE OF SOLUBILITIES IN WATER alumnum n n d ammonum barum d calcum d copper (II) n ron (II) n ron (III) n n d lead magneum d mercury (I) n mercury (II) d potaum lver n odum znc

32 acetate bromde carbonate chlorde chromate hydroxde odde ntrate phophate ulfate ulfde TABLE OF SOLUBILITIES IN WATER alumnum n n d ammonum barum d calcum d copper (II) n ron (II) n ron (III) n n d lead magneum d mercury (I) n mercury (II) d potaum lver n odum znc Legend = noluble SOLID = lghtlysolid oluble = olubleaqueous d = decompoe n = not olated

33 acetate bromde carbonate chlorde chromate hydroxde odde ntrate phophate ulfate ulfde TABLE OF SOLUBILITIES IN WATER alumnum n n d ammonum barum d calcum d copper (II) n ron (II) n ron (III) n n d lead magneum d mercury (I) n mercury (II) d potaum lver n odum znc Legend = old = ueou d = decompoe n = not olated

34 Solublty Rule Mot ntrate are oluble. Mot alt contanng Group I on and ammonum on, NH4, are oluble. Mot chlorde, bromde, and odde alt are oluble, except Ag, Pb2 and Hg Mot ulfate alt are oluble, except BaSO4, PbSO4, Hg2SO4, and CaSO4. 6. Mot ulfde, carbonate, chromate, and phophate are only lghtly oluble. 5. Mot hydroxde except Group 1 and Ba(OH)2, Sr(OH)2, and Ca(OH)2 are only lghtly oluble.

35 Predct f thee reacton wll occur 3 Mg 2 AlCl3 2 Al 3 MgCl2 Can magneum replace alumnum? YES, magneum more reactve than alumnum. Actvty Sere Al MgCl2 No reacton Can alumnum replace magneum? NO, alumnum le reactve than magneum. Actvty Sere MgCl2 Al Therefore, no reacton wll occur. No reacton Order of reactant DOES NOT determne how they react. The queton we mut ak can the ngle element replace t counterpart? metal replace metal or nonmetal replace nonmetal.

36 Sngle-Replacement Reacton Actvty Sere Magc blue-earth Fe CuCl2 Cureplace Cu? Can Fe Ye FeCl2 Znc n ntrc acd Zn 2 HNO3 CanH Zn replace H? Ye 2 Zn(NO 3)2 NO REACTION MgCl2 Br2 Can Br replace Cl? No MgBr 2 General Form A BC AC B Cl2 L Rb K Ba Ca Na Mg Al Mn Zn Cr Fe N Sn Pb H2 Cu Hg Ag Pt Au F2 Cl2 Br2 I2

37 Mole Calculaton Avragado Number = 6.022x1023 atom (partcle) ( ) 1 Mol = 6.022x1023 partcle Smlar to 1 dozen = 12 unt 1 dozen egg = 12 egg 1 dozen cooke = 12 cooke I Mole of Na = 6.022x1023 partcle 1 Mole of H2O = 6.022x1023 partcle

38 Vualzng a Chemcal Reacton 2 Na 10 mole Na Cl2 5 mole Cl2 2 NaCl 10? mole NaCl

39 Proportonal Relatonhp 2 1/4 c. flour 1 tp. bakng oda 1 tp. alt Converon Factor 1 c. butter 3/4 c. ugar 3/4 c. brown ugar 1 tp vanlla extract 2 egg 2 c. chocolate chp Make 5 dozen cooke. I have 5 egg. How many cooke can I make? Rato of egg to cooke 5 egg 5 dozen 2 egg 150 dozen cookecooke = 12.5 Courtey Chrty Johanneon

40 Proportonal Relatonhp Stochometry ma relatonhp between ubtance n a chemcal reacton baed on the mole rato Mole Rato ndcated by coeffcent n a balanced equaton 2 Mg O2 2 MgO Courtey Chrty Johanneon

41 Stochometry Step 1. Wrte a balanced equaton. 2. Identfy known & unknown. 3. Lne up converon factor. Mole rato mole mole Molarrato ma mole mole gram Mole - - mole Molarty - mole lter oln Molar volume - mole lter ga Core tep n all tochometry problem!! 4. Check anwer. Courtey Chrty Johanneon

42 a g at STP Molar Volume a = 2 2. Standard Temperature & Preure 0 C and 4 1 atm L Courtey Chrty Johanneon

43 Molar Volume at STP LITERS OF GAS AT STP Molar Volume (22.4 L/mol) MASS IN GRAMS Molar Ma (g/mol) MOLES partcle/mol NUMBER OF PARTICLES Molarty (mol/l) LITERS OF SOLUTION Courtey Chrty Johanneon

44 Stochometry Problem How many mole of KClO3 mut decompoe n order to produce 9 mole of oxygen ga? 2KClO3 2KCl 3O2? mol 9 mol O2 2 mol KClO3 3 mol O2 9 mol = 6 mol KClO3 Courtey Chrty Johanneon

45 1. 2 Sb 3 Cl2 2 SbCl Mg O2 2 MgO 3. CaCl2 Ca Cl NaClO3 2 NaCl 3 O2 5. Fe 2 HCl FeCl2 H2 6. CuO H2 Cu H2O 7. 2 Al 3 H2SO4 Al2(SO4)3 3 H2

46 2 5 mol 1. 2 Sb 3 Cl2 2 SbCl3 exce 5 mol 7.5 exce x mol mol = 3 x mol 2 x = 15 x = 7. 5 mol x mol How many mole of chlorne ga are requred to react wth 5 mole of antmony? x mol Cl2 = 5 mol Sb 3 mol Cl2 2 mol Sb = 7.5 mol Cl2 How many mole of SbCl3 are produced from 5 mole of antmony and exce Cl2? x mol SbCl3 = 5 mol Sb 2 mol SbCl3 2 mol Sb = 5 mol SbCl3 How many mole of SbCl3 are produced from 7.5 mole of Cl2 and exce Sb? x mol SbCl3 = 7.5 mol Cl2 2 mol SbCl3 3 mol Cl2 = 5 mol SbCl3

47 2. 2 Mg O2 2 MgO 10 mol xl x mol How many mole of magneum oxde are produced from the burnng of 10 mol of Mg? x mol MgO = 10 mol Mg 2 mol MgO 2 mol Mg = 10 mol MgO How many lter of oxygen are needed to burn 10 mol of Mg? Aume 1 mol O2 = 22.4 L x L O2 = 10 mol Mg x L O2 = 10 mol Mg 1 mol O2 2 mol Mg = 5 mol O2 1 mol O L O2 2 mol Mg 1 mol O L O2 1 mol O2 = 112 L O2 = 112 L O2

48 calcum chlorde calcum 3. CaCl2 Ca Cl2 8 mol chlorne x mol How many mole of calcum metal and chlorne ga are produced from the decompoton of 8 mol of calcum chlorde? x mol Ca = 8 mol CaCl2 1 mol Ca 1 mol CaCl2 = 8 mol Ca How many mole of calcum metal and chlorne ga are produced from the decompoton of 8 mol of calcum chlorde? x mol Cl2 = 8 mol CaCl2 1 mol Cl2 1 mol CaCl2 = 8 mol Cl2

49 Meanng of Coeffcent 2 atom Na 1 molecule Cl2 2 molecule NaCl 2 Na Cl2 2 g odum 1 g chlorne 2 mol odum (2 mol Na) x (23 g/mol) 2 NaCl = 1 mol chlorne (1 mol Cl2) x (71 g/mol) 46 g 71 g 117 g 2 g odum chlorde 2 mol odum chlorde (2 mol NaCl) x (58.5 g/mol) 117 g

50 Summary of Clae of Reacton Chemcal reacton Precptaton reacton Oxdaton-Reducton Reacton Acd-Bae Reacton Combuton Reacton Synthe reacton (Reactant are element.) Decompoton reacton (Product are element.)