LAST NAME, FirstCHEM 107 (Spring-2004)Final Exam (100 pts)Name: ------------------------------------------------------------------------, SSN -------------------------------- LAST NAME, First(Circle the alphabet segment of your LAST NAME): A-B C-H I-M N-R S-Z Please answer the following questions:Part I: Multiple Choices (40 pts: 20 @ 2 pts each). Circle the ONE best answer:1. Which of the following molecules is classified as predominantly ionic?a) SiO2 b) ClO2d) P4O10d) CaO 2. Which of the following molecules have bent (angular) molecular shape?I) XeF2II) OF2III) BeF2IV) SF2a) I and II b) only IV c) only II d) II and IV3. Which of the following ions is expected to be paramagnetic? a) Zn2+ b) S2-c) Cu+d) Co2+4. Which of the following has the highest first ionization energy?a) Mg b) Ca c) Se d) Kr5. The ground state electron configuration of hafnium, Hf (Z = 72) isa) [Xe] 5d2 6s2b) [Xe] 4f14 5d2 6s2c) [Xe] 4f14 6d2 6s2d) [Xe] 4f14 5d4 6. Consider four identical 1.0 L flasks containing the following gases each at 25 ˚C and 1 atm pressure. For which gas do the molecules have the highest average velocity? a) SO2b) H2c) O2d) same for all7. What type of hybrid orbitals are used by S in SF4?a) sp b) sp2c) sp3d) sp3d8. Two solutions, A and B, are labeled “0.10 M CaCl2” and “0.20 M CaCl2”, respectively. Both solutions contain the same number of moles of CaCl2. If solution A has a volume of 50 mL. Whatis the volume of solution B?a) 100 mL b) 50 mL1c) 25 mL d) no answer was given9. The oxidation numbers of phosphorus, P in PH3 and P2O74- are:a) -3 and +10, respectively b) -3 and +7, respectively c) -3 and +5, respectively d) +3 and +5, respectively 10. If a gold ring has a mass of 5.50 g in temperature from 25.0 to 28.0 ºC, how much heat is absorbed? (specific heat of gold is 0.129 J/g ºC)a) 2.1 J b) -2.1 J c) 0.24 J d) 130 J 11. Aluminum and oxygen react according to the following equation:4 Al (s) + 3 O2 (g) 2 Al2O3 (s) What mass of Al2O3 (102.0 g/mol), in grams, can be made by reacting 4.6 g of Al with excess oxygen?a) 8.7 g b) 17 gc) 1.2 g d) 35 g12. Which of the following molecules is expected to be polar?a) BeCl2b) CO2 c) SO2d) BCl313. Which name is incorrect?a) Mg(NO3)2: magnesium nitrate b) CoSO4: cobalt(II) sulfatec) Fe2S3: diiron trisulfide d) S2F4: disulfur tetrafluoride 14. Which of the following compounds has a triple bond? a) OPCl2b) SF4c) NH3 d) HCN15. Which of the following molecules is most likely to have bond angle close to 120°?a) NF3b) SF4c) PCl5d) SO3 16. Which of the following is classified as a weak acid? a) HBr b) NaOH c) MgF2d) HF17. Compact disc players use lasers that emit red light with a wavelength of 685 nm. What is the energy of a mole of photons in kilojoule?a) 175 b) 2.9 x 10-192c) 2.73 x 10-13d) no answer was given18. The assumptions of the kinetic-molecular theory (KMT) are most likely to be correct under what conditions?a) high temperature – high pressureb) high temperature – low pressurec) low temperature – low pressured) always correct19. Consider the phase diagram for CO2. In going from point A to B to C:a) liquid CO2 becomes solid.b) gaseous CO2 becomes solid.c) solid CO2 becomes liquid.d) liquid CO2 becomes gaseous. 20. Consider the phase diagram for CO2. In going from point A to point B:a) fusion followed by evaporationb) fusion followed by sublimation.c) sublimation followed by condensation.d) evaporation followed by fusion. Phase diagram of CO2Part II. Bonding and Chemical Equations (28 pts):A) Bonding & molecular structure (14 pts):1. Draw the Lewis structure for the nitrite ion, NO2-, draw the resonance structures, if there is any then:predict: a) the molecular shape of the ion b) hybridization of the central atom c) number σ and π bonds d) bond angle3Lewis Structure & resonance structures (if any)a) Molecular shape: ------------------------b) Hybridization of the central atom: -------c) # of σ bonds ------- and # of π bonds --------d) Bond angle: -----------------B) Chemical Equations (14 pts):1. Write the chemical equation and the net ionic equation for the reaction between aqueous solutions of Na2SO4 and Ba(OH)2 and then identify the spectator ion(s)2. Write the balanced chemical equation for the reaction, if any occurs between aqueous solutions of FeCl3 and NaNO3 (write N.R. if they do not react; no chemical equation) 3. Balance the following redox equation in acidic solution:NO3- (aq) + Cu (s) NO2 (g) + Cu2+ (aq),Then identify the oxidizing agent and how many electron(s) are transferred per one mole of the oxidizing agent.4Balanced equation:Oxidizing agent: --------------Number of electrons/mole of oxidizing agent: -------- Chemical equation:Net ionic equation:Spectator ion(s):Chemical equation:Part III. Calculations (32 pts: 4 @ 8 pts) Show all work for full credit. Please express all answers with the proper units and correct number of significant figures.1. Exactly 20.0 g of SiO2 and 7.00 g of C are allowed to react according to the balanced equation:SiO2 (s) + 3 C (s) SiC (s) + 2 CO (g) a) Determine the limiting reactant then b) What is the maximum amount of carbon monoxide that can be formed?a) If you perform the experiment and isolate 4.50 g CO, what is the percent yield? 5c) Percent yielda) Limiting reactant b) Theoretical yield of CO2. Strychnine, a deadly poison has a molecular mass of 344 and a percentage composition 75.42% C,6.63% H, 8.38 % N and the balanced oxygen. Determine the simplest and molecular formulas of thecompound. 3. An important chemical reaction in the manufacture of Portland cement is the higher temperaturedecomposition of calcium carbonate to give calcium oxide and carbon dioxide CaCO3 (s) CaO (s) + CO2 (g) Suppose a 1.25 g of CaCO3 is decomposed by heating. How many milliters of CO2 gas will beevolved, if it will be measured at 740 torr and 25ºC?Molecular FormulaC21H22N2O2Simplest FormulaC21H22N2O26Volume of CO2 314 mL4. a) Carbon monoxide is often used in metallurgy to remove oxygen from metal oxides and thereby givethe free metal. The thermochemical equation for the reaction of CO