Instructions for AP/IB 2 Chem Summer Assignment

Transcription

1 Instructions for AP/IB 2 Chem Summer Assignment Note: Future AP/IB chemistry students are expected to learn the material in this packet before class starts in the fall. Most of this is a review of names, formulas and reactions that were learned in pre-ap/ib chemistry. Since this class is AP and IB chemistry combined, there will not be enough time to review this material in class. Study the examples before completing the questions. For more detailed information, download the chemical reactions power point from my webpage (AP/IB 2 chemistry). Or go back and review your Chem I notes on ionic bonding, covalent bonding and chemical reactions. This assignment will count as a major grade and is due the second day of class. It will be spot checked for correctness (i.e. it s not just a completion grade; it will be scanned and points deducted for things that are obviously not even close to the correct answer).

2 AP/IB 2 Chemistry: Summer Assignment Name Memorize these element names and symbols: H= hydrogen He = helium Li = lithium Be = beryllium B = boron C = carbon N = nitrogen O = oxygen F = fluorine Ne = neon Na =sodium Mg = magnesium Al = aluminum Si = silicon P = phosphorus S = sulfur Cl = chlorine Ar = argon K = potassium Ca = calcium Sc = scandium Ti = titanium V = vanadium Cr = chromium Mn = manganese Fe = iron Co = cobalt Ni = nickel Cu = copper Zn = zinc As = arsenic Se = selenium Br = bromine Kr = krypton Rb = rubidium Sr = strontium Pt = platinum Ag = silver Cd = cadmium Sb = antimony I = iodine Xe = xenon Cs = cesium Ba = barium Au = gold Hg = mercury Sn = tin Pb = lead Rn = radon Ra = radium U = uranium Pu = plutonium Bi = bismuth Memorize these ion oxidation numbers: A groups: generally metals are cations (+) and nonmetals are anions (-) Group # Oxidation # examples 1 A (alkali metals) +1 Li +, Na +, K + 2 A (alkaline earth metals) +2 Mg 2+, Ca 2+, Ba 2+ 3 A +3 Al 3+, Ga 3+, In 3+ 4 A +4 or -4 (depends) C 4+, C 4-5 A -3 (except Bi 5+ ) N 3-, P 3-, As 3-6 A -2 O 2-, S 2-, Se 2-7 A (halogens) -1 F -, Cl -, Br -. I - 8 A (noble gases) No ions; no compounds names end in ide Ex: oxide, chloride B groups (and tin and lead): Transition metals; most have multiple oxidation numbers Ag +, Zn 2+, Cd 2+, Hg +, Hg 2+, Cu +, Cu 2+ Fe 2+, Fe 3+, Co 2+, Co 3+, Cr 2+, Cr 3+, Cr 6+ Ni 2+, Ni 3+ Mn 2+, Mn 3+, Mn 4+, Mn 7+ V 2+, V 3+, V 4+, V 5+ Pb 2+, Pb 4+, Sn 2+, Sn is most common

3 Polyatomic ions (Memorize these!): NO 3 - = nitrate CN - - = cyanide MnO 4 = permanganate NO - 2 = nitrite SCN - = thiocyanate - IO 3 = iodate BrO - 3 = bromate SO 2-4 = sulfate HSO - 4 = hydrogen sulfate S 2 O 2-3 = thiosulfate (bisulfate) NH + 4 = ammonium SO 2-3 = sulfite HSO - 3 = hydrogen sulfite 2- C 2 O 4 = oxalate (bisulfite) OH - = hydroxide 3- PO 4 = phosphate HPO 2-4 = hydrogen phosphate 2- CO 3 = carbonate PO 3-3 = phosphite H 2 PO - 4 = dihydrogen phosphate HCO - 3 = hydrogen carbonate (bicarbonate) ClO - 3 = chlorate ClO - 4 = perchlorate CrO 2-4 = chromate ClO - 2 = chlorite ClO - = hypochlorite Cr 2 O 2-7 = dichromate C 2 H 3 O 2 - or CH 3 COO - acetate or ethanoate Determining the formula of a compound: I. Ionic Compounds (have a metal and a nonmetal). Use the oxidation numbers to put the ions together in the correct lowest whole number ratio. Ex: sodium oxide Na + and O 2- = Na 2 O iron (III) chloride Fe 3+ and Cl - = FeCl 3 (roman numeral III means +3) zinc sulfate Zn 2+ and SO 4 2- = ZnSO 4 aluminum hydroxide Al 3+ and OH - = Al(OH) 3 use ( ) if 2 or more of polyatomic ion You try; write the formula 1. sodium phosphate 2. ammonium bromide 3 lead (II) nitrate 4. silver sulfide 5. calcium carbonate 6. potassium dichromate

4 II. Covalent Compounds (have 2 nonmetals; no ions; atoms share electrons) Use the prefixes to determine the number of atoms (1= mono, 2 = di, 3 =tri, 4 tetra, 5= penta, 6 = hexa) Ex: carbon tetrachloride = CCl 4 dinitrogen tetroxide = N 2 O 4 You try; write the formula 7. carbon dioxide 8. diphosphorus pentoxide 9. sulfur hexafluoride 10. sulfur trioxide III. Acids (have H + with an anion) put the ions together like the ionic ones. There are 6 strong acids (these dissociate completely in aqueous solution; ex: HCl exists as H + and Cl - ions, not as molecules) Memorize the six strong acids: HCl, HBr, HI, HNO 3, H 2 SO 4, HClO 4 All others are weak! (dissociate only slightly into ions) Ex: hydrochloric acid: H + and Cl - = HCl hydro..ic has the ide ion (strong) nitric acid; H + and NO - 3 = HNO 3 -ic has ate ion (strong) nitrous acid H + - and NO 2 = HNO 2 -ous has the ite ion (weak) You try; write the formula and indicate if weak or strong 11. acetic acid (ethanoic) 12. hydrofluoric acid 13. carbonic acid 14. hypochlorous acid 15. perchloric acid 16. sulfuric acid

5 Naming Compounds I. Ionic: Name the metal, then the nonmetal; change the ending to ide, -ite, or ate depending on the identity of the anion. Indicate the oxidation number if it has one of the metals with more than one oxidation number. Ex: KI = potassium iodide Ag 2 SO 3 = silver sulfite CuCl 2 = copper(ii) chloride Al 2 O 3 = aluminum oxide (NH 4 ) 2 Cr 2 O 7 = ammonium dichromate Fe 3 (PO 4 ) 2 = iron(ii) phosphate You try; name the compound 17. ZnO 18. KMnO NaClO NH 4 OH 21. LiH 2 PO PbSO AlBr Ba(C 2 H 3 O 2 ) SnCl Cu(NO 3 ) CdS 27. SrCrO CaC 2 O NaCN II. Covalent Compounds (Binary compounds: 2 nonmetals) Use prefixes to indicate the number of atoms (don t use mono on the first element) Prefixes: mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca ending is -ide Ex: SiF 4 = silicon tetrafluoride S 2 Cl 2 = disulfur dichloride 30. CO 31. PCl N 2 O CS 2

6 Types of Chemical Equations: Writing Chemical Reactions Learn the general formula for each type of reaction. If the reaction occurs in water solution, you must give the net ionic equation. If it doesn't occur in aqueous solution, the atoms/molecules do not exist as ions. Writing the net ionic equation (water solution only!) 1. First memorize the six strong acids and solubility rules for salts (ionic compounds). Strong Acids hydrochloric, hydrobromic, hydroiodic, sulfuric, nitric, perchloric these are completely dissociated into ions so write them as separated ions: ex: HCl is really H + and Cl - HNO 3 is really H + and NO 3 - do not write weak acids like this! acetic acid stays as HC 2 H 3 O 2 Solubility Rules i) soluble salts: all nitrates, acetates, alkali metals compounds and ammonium compounds are always soluble (no exceptions). ii) insoluble salts: compounds of lead, silver, cadmium and mercury (except those trumped by rule i ) iii) Compounds of calcium, barium, strontium and transition metals are insoluble except halides (and those trumped by rule i) These three rules don't cover every possible compound, but they include most compounds that appear on the AP or IB test. So write soluble compounds as separated ions. Insoluble compounds precipitate from the solution as a solid. Do not separate the ions for a solid. ex: calcium nitrate, Ca(NO 3 ) 2 is soluble so it exists as Ca 2+ and 2 NO 3 - in solution lead (II) hydroxide is insoluble so keep it as Pb(OH) 2

7 2. Write the complete equation predicting the products. 3. Cancel the spectator ions. These are ions that are unchanged (must be exactly the same form on both sides of the equation. 4. Balance the equation using lowest whole number coefficients. Double Replacement Reaction: AB + CD AD + CB (occurs in solution always) Ex: aqueous solutions of silver nitrate and sodium carbonate are mixed. Ag + + NO Na + + CO 3 2- Ag 2 CO 3 + Na + + NO 3 - silver carbonate is insoluble sodium nitrate is soluble net ionic: 2 Ag + + CO > Ag 2 CO 3 sodium and nitrate are spectator ions; they cancel out and should not appear in the answer Ex: aqueous solutions of barium chloride and copper(ii) sulfate are mixed Ba 2+ + Cl - + Cu 2+ + SO 4 2- BaSO 4 + Cu 2+ + Cl - barium sulfate is insoluble copper(ii) chloride is soluble net ionic: Ba 2+ + SO > BaSO 4 copper and chloride are spectator ions Ex: 1-molar hydrochloric acid is neutralized by an equal volume of 1-molar potassium hydroxide H + + Cl - + K + + OH - K + + Cl - + H 2 O potassium chloride is soluble; water is not an ionic compound (not made of ions) leave it intact net ionic: H + + OH - ---> H 2 O potassium and chloride are spectator ions

8 You try: Write the net ionic equation for these double replacement reactions: 34. A solution of lead(ii) nitrate is added to a solution of sodium iodide. 35. Solutions of calcium acetate (ethanoate) and lithium phosphate are mixed 36. Equal volumes of equimolar nitric acid and sodium hydroxide solutions are mixed 37. A few drops of aqueous nickel (II) nitrate are added to a solution of sodium sulfide 38. Some acetic acid (ethanoic acid) is added to sodium hydroxide solution.

9 Single Replacement Reaction: A + BC AC + B or BA + C these occur in aqueous solution so give the net ionic form. Ex: a piece of zinc metal is placed in a solution of copper(ii) sulfate Zn + Cu 2+ + SO 4 2- Zn 2+ + SO Cu zinc sulfate is soluble copper product is solid, metallic copper net ionic: Zn + Cu 2+ Zn 2+ + Cu sulfate is a spectator ion; don't cancel the solid metal and its dissolved ion (they are different forms) Ex: chlorine gas is bubbled through a solution of lithium bromide Cl 2 + Li + + Br - Br 2 + Li + + Cl - lithium chloride is soluble chlorine gas and elemental bromine are both diatomic (HOBrFINCl) elements net ionic: Cl Br - ---> Br Cl - lithium ions are spectator ions Ex: a piece of magnesium metal is added to a solution of sulfuric acid Mg + H + + SO 4 - Mg 2+ + SO H 2 magnesium sulfate is soluble net ionic : Mg + 2 H + ---> Mg 2+ + H 2 sulfate is spectator; can't cancel solid magnesium metal with dissolved magnesium metals displace hydrogen from an acid. ion! hydrogen gas is diatomic Ex: sodium metal reacts with water Na + H 2 O NaOH + H 2 sodium hydroxide is soluble; net ionic: Na + 2 H 2 O ----> Na OH - + H 2 alkali metals and alkaline earth metals react with water to form hydrogen gas. This is why sodium explodes in water.

10 You try: Write the net ionic equation for these single replacement reactions 39. A piece of copper wire is placed in a test tube containing silver nitrate solution. 40. Elemental bromine is added to a solution of potassium iodide. 41. Zinc metal is placed in a solution of hydrochloric acid. 42. Calcium metal is added to water. 43. A piece of nickel metal is placed in a solution of copper(ii) nitrate 44. A small piece of potassium metal is dropped in a beaker of water. 45. Magnesium metal reacts with a solution of acetic acid (ethanoic acid)

11 Synthesis Reaction: A + B AB don't need the net ionic form usually do not occur in water solution Ex: A piece of aluminum metal is dropped into a container of iodine vapor. 2 Al + 3 I 2 2 AlI 3 iodine is diatomic; if metal with nonmetal, use oxidation numbers to get the ionic compound formula Ex: Sulfur trioxide gas is streamed into a flask containing calcium oxide SO 3 + CaO CaSO 4 two simple compounds make a more complex compound; make sure the product is an actual compound Ex: Nitrogen gas reacts with hydrogen gas in the presence of an iron catalyst Fe 3 H 2 + N 2 2 NH 3 The Haber Process (know this one by heart!) Ex: Carbon dioxide gas is bubbled through water CO 2 + H 2 O H 2 CO 3 nonmetal oxides always react with water to make an acid Ex: Magnesium oxide is added to water MgO + H 2 O Mg(OH) 2 metal oxides react with water to make a base net ionic: MgO + H 2 O ----> Mg OH - this is in water and magnesium hydroxide is slightly soluble

12 You try: Write balanced equations for these reactions 46. Calcium metal reacts with nitrogen gas 47. A piece of aluminum foil is added to a container of liquid bromine 48. Hydrogen gas reacts with chlorine gas 49.Sulfur trioxide gas is bubbled through water 50. Solid calcium oxide is added to water 51. Elemental carbon combines with oxygen gas. Decomposition Reaction: AB A + B usually do not occur in solution Ex: Mercury (II) oxide is heated. 2 HgO 2 Hg + O 2 Ex: Molten sodium chloride is electrolyzed 2 NaCl 2 Na + Cl 2 Ex: Hydrogen peroxide decomposes in the presence of a manganese (IV) oxide catalyst. MnO2 2 H 2 O 2 2 H 2 O + O 2 Know this reaction!!

13 Ex: Calcium carbonate is heated CaCO 3 CaO + CO 2 metal carbonates decompose into the metal oxide and carbon dioxide gas Ex: Sodium chlorate is heated 2 NaClO 3 2 NaCl + 3 O 2 metal chlorates decompose into the metal chloride and oxygen gas Ex: Hydrochloric acid solution is added to solid sodium bicarbonate HCl + NaHCO 3 NaCl + H 2 CO 3 this occurs in solution so need net ionic form H + + Cl - + NaHCO 3 Na + + Cl - + H 2 O + CO 2 this reaction is double replacement and decomposition; carbonic acid sodium bicarbonate is a solid (not dissolved) breaks down into water and carbon do not separate a solid into ions dioxide. net ionic: H + + NaHCO 3 ---> Na + + H 2 O + CO 2 You try: Write reactions for these decomposition reactions. 53. Molten aluminum oxide is electrolyzed. 54. Electrolysis of water 55. Solid sodium carbonate is heated.

14 56. Solid potassium chlorate is heated. 57. A catalyst of potassium iodide is added to hydrogen peroxide 58. Several drops of nitric acid are added to solid calcium carbonate Combustion Reaction: C x H y O z + O 2 CO 2 + H 2 O (complete; enough O 2 ) when insufficient oxygen, it also produces CO and C You should know names and formulas of common organic compounds. See the power point on organic chemistry on my web page (on pre-ap chem tab) Ex: butane gas burns in an excess amount of oxygen 2 C 4 H O 2 8 CO H 2 O Ex: Complete combustion of ethanol C 2 H 5 OH + 3 O 2 2 CO H 2 O You try: Write reactions for these combustion reactions: 59. Complete combustion of propane gas 60. Complete combustion of methanol