115 Test Out Study GuideFeb2010

PURDUE UNIVERSITY Study Guide for CHEM I (Chemistry 11500) This study guide describes the topics that should be mastered before you attempt the examination for credit in Chemistry 115. The material can be found in a number of books on the market. A list of possible textbooks is given below. ******************************************************************************* IMPORTANT: 1. Read this material thoroughly if you expect to try for advanced placement and extra credit which counts towards graduation. 2. Study the material listed in the outline. 3. Work as many practice problems as possible. 4. When you feel prepared to take the test-out exam, try the sample exam at the end of this study guide first. 5. Come to the examination rested and confident. ******************************************************************************** The subject matter of a general chemistry course varies somewhat from institution to institution. Chemistry 11500 at Purdue University deals with chemical formulas, chemical equations, and the mole concept; chemical calculations including gram-mole and gram-gram calculations; the properties of gases and the kinetic molecular theory of gases; the properties of liquids and solids; semi-conductors; periodic chemistry; electrons in atoms and molecules; nuclear chemistry and reactions; Lewis structures and molecular geometry; and the energetics of chemical reactions. Many of these concepts are closely related. The mole concept is used extensively in studies of liquids, gases, and solids, while an understanding of electronic structure is essential for discussions of periodic chemistry, chemical bonding, oxidation and reduction reactions, and molecular geometry. The topics presented in this outline should be studied before you attempt the sample exam at the end of this study guide. These topics are listed under headings according to those found in the text currently in use at Purdue. They may not appear in exactly this order in the textbook you study. In preparing for the examination it is important to work as many problems as possible. The purpose of these problems must be understood, however. They should be used to measure your understanding of the concepts and principles involved, and not to test your ability to recall formulas or facts. Our examinations are designed to test whether you understand concepts rather than whether you remember formulas such as P1V1 = P2V2. Knowledge of a limited number of equations, a clear understanding of what they mean and how they can be used, and an understanding of definitions of basic concepts such as the mole, density, pressure, etc., should be sufficient to handle the vast majority of the problems encountered. At the end of this study guide you will find a sample examination. Allow 90 minutes for the exam. The exam does not cover every point in the outline, since no examination can do that. However, if you have no difficulty with the sample exam, you should not have any difficulty with the examination for credit. The answers to the exam are given on the last page of this Study Guide. To help you estimate how well you are doing, note that 55% is considered passing. (Revised Feb 2010) Chem 11500 Test-out Exam Study Guide 2 A word of advice concerning the taking of the actual examination for credit. No one can do well on an exam when excessively fatigued. You should therefore try to rest before taking the exam for credit. If your trip to campus requires travel into the late hours of the night, or a very early departure from your home, you might be advised to allow for one nights rest in the Lafayette area before taking the examination. Many students who are unsuccessful with the examination tell us that failure to take this advice contributed to their inability to complete the examination successfully. Please consult your advanced credit schedule for both the time and place of the examination. Suggested Textbooks: Chemistry & Chemical Reactivity, 7th ed by Kotz, Treichel & Townsend; Thomson/Brooks/Cole. ISBN-13: 978-0495390299. Chemistry: The Molecular Nature of Matter and Change, 5th edition by Silberberg; McGraw-Hill. ISBN-10: 0077216504; ISBN-13: 978-0077216504. Chemistry, the Central Science by Brown, 11th edition by LeMay, Bursten & Murphy; Prentice-Hall. ISBN-13: 978-0136006176. Chem 11500 Test-out Exam Study Guide 3 CHEMISTRY 11500 STUDY GUIDE 1. The mole, chemical formulas, and chemical equations. You should know the relationships between a mole of material and its weight, volume, concentration, or the number of atoms or molecules. You should be able to write the correct formula given the name of any "common" chemical compound; or given the formula, write the name. Given the formula for any compound you should be able to: (a) (b) (c) (d) name the elements that make up the compound. indicate the number of each kind of atom represented. determine the mass of each element in one mole of compound. calculate the molecular weight. Given the weight of a sample and the formula of the compound, you should be able to calculate: (a) (b) (c) (d) 2. the number of moles of the compound in the sample. the number of moles of any one element in the sample. the number of molecules in the sample. the number of atoms of any one element in the sample. Chemical stoichiometry Starting from Avogadro's hypothesis that equal volumes of gases under the same conditions contain the same number of gas molecules, and any two of the following pieces of information, you should be able to calculate the third. (a) the ratio between the volume of gaseous reactants and products (b) the formulas of the products (c) the formulas of the reactants For example: One volume of hydrogen (H2) reacts with one volume of chlorine (Cl2) to produce two volumes of hydrogen chloride. What is the formula of hydrogen chloride? Given the mass of each element in a sample of a compound of known weight you should be able to determine the percent by weight of each element. Given the percent by weight of each element in a compound, you should be able to determine the simplest or empirical formula for the compound. Given all reactants and products for a chemical reaction, and any one of the following pieces of information, you should be able to calculate any other piece of information on the list. (a) (b) (c) (d) (e) the number of moles of one of the products or reactants. the mass of any product or reactant. the number of molecules of any product or reactant. the number of atoms or mass of any single element involved. the concentration and volume of a solution of reactant or product. Given the weight of two or more reactants or products in a chemical reaction you should be able to identify the limiting reagent, calculate the weight of any reactant consumed in the reaction, calculate the weight of any product produced in the reaction, and determine the weight of the excess reactant left over when the reaction has reached completion. Chem 11500 Test-out Exam Study Guide 3. 4 Properties of gases. Given any three of the following pieces of information, you should be able to calculate the fourth, assuming that the gas is ideal. (a) (b) (c) (d) the number of moles of gas, or the weight of the gas the pressure of the gas the volume of the gas the temperature of the gas Given the volume of a gas at one temperature and pressure, you should be able to find the volume it would occupy at another temperature and pressure. You should be able to determine the density of a gas from the pressure and temperature. You should be able to determine the molecular weight of a gas from its density. From the equation for a reaction involving a gas, and the mass, moles or volume of a gaseous reactant, you should be able to find the mass, moles or volume of any other product or reactant. You should be able to describe the conditions under which a real gas such as H2 or CO2 will deviate from ideal gas behavior. When confronted with a situation in which a real gas does not obey the Ideal Gas Law, you should be able to identify the assumption(s) of the kinetic theory of gases that does not hold in that situation. Given the total pressure of a gas mixture, and the partial pressure of all components except one, you should be able to find the partial pressure of the remaining component using Dalton's law. If you know the mole fraction of each gas in a mixture, and the total pressure, you should be able to find the partial pressure of each component. 4. Properties of liquids. You should be able to use a microscopic or atomic/molecular scale model to describe the changes which occur when a solid becomes a liquid, or when a liquid becomes a gas. You should be able to explain the differences in the arrangements of the atoms or molecules, what happens to the average speed of the particles, what changes occur in the distance between particles, and the temperature changes that must occur. You should be able to describe several physical properties of liquids which are characteristic of these substances and which can therefore be used to identify an unknown. You should be able to describe how you would measure each of these properties. You should be able to describe the differences between solids, liquids and gases in terms of macroscopic properties such as density, compressibility, viscosity and vapor pressure. You should be able to describe the effect that varying any of the following will have on the vapor pressure of a liquid. (a) (b) (c) (d) volume of the liquid surface area of the liquid volume of gas over the liquid temperature Chem 11500 Test-out Exam Study Guide 5 You should be able to describe the processes that must occur in order for a substance to dissolve in a solvent. You should be able to decide whether the energy associated with that process favors dissolution. You should know how to prepare a specified volume of a solution of known concentration, e.g., 200 mL of 0.100 M NaCl. You should be able to calculate the number of moles or the mass of solute dissolved in a given volume of solution of known concentration, e.g., how many grams of NaCl are present in 50.0 mL of a 1.50 M solution? You should be able to use a solution of known concentration to prepare a solution of a lower concentration by dilution, e.g., prepare 100 mL of 0.22 M HCl starting with a solution that is 2.50 M HCl. Given the vapor pressure of a pure solvent at some temperature, you should be able to find the vapor pressure of that solvent over a solution with a specified mole fraction of solvent. Given the boiling point of a pure solvent, its molal boiling point elevation constant, and the molality of the solution, you should be able to calculate the boiling point of the solution. Conversely, you should be able to find the molality of a solution from the boiling point of that solution. You should be able to find the molecular weight of a solute from the molality of the solution, the boiling point of the solution, the boiling point of the pure solvent, and the molal boiling point elevation constant. You should be able to calculate the freezing point of a solution from the freezing point of the pure solvent, its molal freezing point depression constant, and the molality of the solution. You should be able to find the molecular weight of a solute from the molality of the solution, the freezing point of the solution, the freezing point of the pure solvent, and the molal freezing point depression constant. 5. Properties of solids. You should be able to describe a crystalline solid, the concept of the unit cell, the three cubic unit cells, and the concept of coordination number. You should be able to calculate any of the following quantities from some or all of the other measurements. (a) (b) (c) (d) (e) (f) (g) unit cell edge locations of atoms interatomic distances density of the solid number of formula units per unit cell type of cubic crystal lattice coordinates of the atoms in the unit cell You should be able to describe a semiconductor, and know the differences between n and p-type. 6. Periodic chemistry. You should understand the concept of oxidation number. You should be able to give the common oxidation numbers of any element by referring only to the Periodic Table for any element in Groups IA, IIA, IIIA, IVA, VA, VIA, VIIA or VIIIA. You should be able to assign oxidation numbers to each element in a compound from the chemical formula for the compound. You should be able to write the formula, including the proper charge, for each of the following anions: perchlorate, chlorate, chlorite, hypochlorite, permanganate, dichromate, chromate, cyanide, oxalate, acetate, hydroxide, sulfate, sulfite, carbonate, nitrate, nitrite, and phosphate. Chem 11500 Test-out Exam Study Guide 6 You should be able to indicate whether a property such as melting point, density, ionization energy, electronegativity, atomic weight, or atomic radius increases or decreases as we proceed down a column or across a row of the Periodic Table. You should be able to predict which of two elements in the same column or row will have the higher (a) electronegativity (b) atomic radius (c) ionization energy You should be able to use the Periodic Table to predict the formula of the hydride (e.g. CH4, NH3 ) or oxide (CO2 , N2 O5 ) of a given element. 7. Electronic structure of atoms. Given the symbol for an element or ions, and a Periodic Table, you should be able to indicate the number of protons in the nucleus of that particle, and the number of electrons around the nucleus. From the atomic mass you should be able to deduce the number of neutrons as well. From the position of the element in the Periodic Table you should be able to indicate the number of electrons in the outer or valence shell. Conversely, knowing the number of electrons in the valence shell, you should be able to identify the family or Group to which the elements belongs. You should be able to name the four quantum numbers that are used to designate individual electrons in an atom, and you should be able to describe the limits on the values that may be assumed by each quantum number. You should be able to indicate the values of the quantum number which correspond to s, p, d or f orbitals. You should be able to draw diagrams which represent s, p or d orbitals. For any value of the principle quantum number, n, you should be able to indicate the maximum number of electrons that may occupy that energy level. You should be able to identify the orbitals that contain the valence electrons for any element in the Periodic Table. From the atomic number of an element or from a Periodic Table, you should be able to write the electronic configuration for any element, i.e., ls2 2s2 2p6...etc. 8. Chemical bonding and related topics. Given the symbol, name or atomic number for any element, you should be able to write the Lewis structure of that element. You should be able to write the Lewis or electron dot structure for any compound containing no more than three elements. From the chemical and physical properties of a compound, e.g., the conductivity, melting point, heat of fusion, etc., you should be able to predict whether that compound is ionic or covalent. Given a sample of an unknown compound, you should be able to describe a series of tests that you could perform that would help you decide whether the compound is ionic or covalent. You should be able to use a table of electronegativities to determine where the bond between two elements would best be described as ionic or covalent. Chem 11500 Test-out Exam Study Guide 7 You should be able to predict the relative size of ions and the atoms from which these ions are produced. Using the Periodic Table you should be able to predict which of two ions would have the larger radius. Using values for the radii of ions and/or the Periodic Table you should be able to predict which ionic compound will have the largest crystal lattice energy, e.g., which has the higher crystal lattice energy, Na2O or MgO? From the electron-dot or Lewis structure of a molecule you should be able to identify the distribution of bonding and non-bonding electron pairs. You should be able to predict the shape of the molecule. If there are several acceptable Lewis structures for a given molecule, you should be able to write all possible resonance structures, and understand the implication of the existence of these resonance structures. You should be able to identify the atomic orbitals that are used to form bonds in covalent molecules. For example, when HF forms, what atomic orbitals overlap to form the bond? You should be able to draw diagrams that show how atomic orbitals overlap to form double and triple bonds, and you should be able to identify the atomic orbitals that form the sigma and pi bonds in these compounds. You should understand what is meant by hybrid atomic orbitals. and the shape of molecules that use sp, sp2, sp3, dsp3, or d2sp3 hybrid orbitals. 9. Chemical energetics. You should be able to distinguish between exothermic and endothermic reactions, between reactions which lose heat and which gain heat from their surroundings, and reactions which should be identified by ÄH = – or ÄH = +. You should be able to describe the conditions that are implied for solids, liquids, and gases when values of the standard state enthalpy, ÄH, are given. Given an equation and the standard enthalpy of formation of each compound in the reaction, you should be able to calculate the change in the enthalpy for the reaction. (Note, this is only one of many different kinds of problems in which Hess' Law can be applied.) You should be able to set up reactions in the form of a series of small "steps" starting with the reactants and ending up with the products, and construct an enthalpy of reaction from these steps. You should be able to use bond dissociation energies to estimate the enthalpy of reaction for reactions in which enthalpy of formation data are not available for all reactants and products. 10. Nuclear chemistry and reactions You should understand the meaning of radioactivity, nucleon, nuclide and isotope. Describe the characteristics of radioactive emissions. Use the concepts of radioactive decay and half-life to find the age of an object, decay constant half-life, or amount of material remaining. Chem 11500 Test-out Exam Study Guide 8 Sample Test for Chemistry 11500 1. 2. 3. 4. 5. This exam consists of 47 multiple choice questions. For each question mark the one best answer. Allow 90 minutes for this sample exam. During the actual examination for credit, a list of the elements and their atomic weights will be provided. You should use such a list (not a Periodic Table) for this exam. The answers may be found on the last page. Questions 1-6 pertain to the following hydrocarbon combustion reaction: C7 H16 + 11 O2 ÿ 7 CO2 + 8 H2 O ____ 1. What is the weight of a mole of C7H16 ? (a) 22.4 (b) 86.1 (c) 100.2 (d) 716 (e) 1102.2 Make sure of this answer since the next five depend on it! ____ 2. How many moles of CO2 will be produced by the combustion of 30 g of C7H16 ? (a) 210 ____ 3. (e) 3.3 (b) 2.1 L (c) 15.7 L (d) 5.22 L (e) 47.1 L (b) 8.92 g/L (c) 2.23 g/L (d) 1.12 g/L (e) 100 g/L What weight of H2 O would be formed by the combustion of 20 g of C7H16 ? (a) 3.6 g ____ 6. (d) 0.3 The density of C7 H16 at 273EC and 2 atmospheres pressure would be: (a) 4.46 g/L ____ 5. (c) 2.1 If the prevailing temperature is OEC and the prevailing pressure 3 atmospheres, what volume of CO2 can be produced from 10 g of C7H16? (a) 0.7 L ____ 4. (b) 21 (b) 160 g (c) 144 g (d) 28.8 g (e) 62 g 1 mole of C7H16 and 11 moles of O2 are caused to react in a closed container at such a temperature that all reactants and products are gases. The final pressure is: (a) (b) (c) (d) (e) the same as the initial pressure. 5/4 times the initial pressure. 15 times the initial pressure. 15/11 times the initial pressure. 15/12 times the initial pressure. Chem 11500 Test-out Exam Study Guide ____ 7. If a single molecule of a substance weighs 5.34 x 10 – 23 g, the molecular weight must be: (a) 28.1 ____ 8. (b) 32.14 The difference between (a) (b) (c) (d) (e) ____ 9. 9 (c) 56.2 and (d) 64.28 (e) 128.56 is: one electron. one proton. one electron and one proton. one neutron. not distinguishable. A 1986 penny of mass 2.48 g is 6% copper by mass. How many copper atoms [AW Cu = 63.55] are contained in the penny? (a) 2.34 x 10 –3 (d) 3.613 x 1022 (b) 3.81 (e) 1.41 x 1021 (c) 6.022 x 1023 ____ 10. Ammonia (NH3) reacts with O2 as follows: 4 NH3 + 5 O2 ÿ 6 H2O + 4 NO How many liters of O2 (at STP) react with one mole of NH3? (a) 5 L (d) 5 x 22.4 L 4 (b) 5 x 22.4 L (e) 10 x 22.4 L 9 (c) 4 x 22.4 L ____ 11. Hydrazoic acid, HN3 , decomposes qualitatively on heating as follows: 2 HN3 ÿ 3 N2 + H2 If the initial pressure is 3 atm, what is the final pressure assuming the temperature and volume remain the same? (a) 6 atm ____ 12. (b) 8 atm (c) 9 atm (d) 3 atm (e) 1.5 atm Which of the following properties of an alcohol/water mixture is independent of temperature? (a) density (b) viscosity (c) volume percent (d) molarity (e) mole fraction Chem 11500 Test-out Exam Study Guide 10 ____ 13. Which of the following contains the largest number of carbon atoms? (a) (b) (c) (d) (e) ____ 14. 0.25 moles carbon monoxide, CO 0.1 moles ethanol, C2H5OH 0.05 moles glucose, C6H12O6 0.01 moles sucrose, C12H22O11 0.01 moles diamond, C Which of the following graphs will not be a straight line? All parameters are held constant except for those plotted. (a) measured pressure as a function of temperature. (b) measured pressure as a function of volume. (c) measured pressure as a function of moles of gas. (d) measured volume as a function of temperature. (e) measured volume as a function of moles of gas. ____ 15. Which of the following properties of gases is directly proportional to molecular weight at STP? (a) the rate of effusion (b) the time for effusion (c) the density ____ 16. 3 g of H2, 16 g of O2 and 7 g of N2 are introduced into a 22.4 L container at OEC. What total pressure in atmospheres results? (a) 1.00 ____ 17. (b) 1.75 (c) 2.00 (d) 2.25 (e) 2.75 Gas A has a temperature of 273 K while gas B is at 300 K. Which of the following statements must be true? (a) (b) (c) (d) (e) ____ 18. (d) the viscosity (e) the thermal conductivity The volume of A is less than that of B. The density of A is greater than that of B. The pressure of A is less than that of B. The rate of change of momentum per unit area is greater for gas A than for gas B. The average kinetic energy of molecules of gas B is greater than that of gas A. Oxygen, O2 , has a molecular weight of 32 and sulfur dioxide, SO2 , of 64. The average velocity (u)) of sulfur dioxide is: (a) 2 times that of O2 . (d) (b) (e) 1/2 that of O2 . times that of O2 . (c) the same as that of O2 . that of O2 . Chem 11500 Test-out Exam Study Guide ____ 19. 11 Which of the following reactions is most exothermic as written? (a) H2 (g) ÿ 2 HE(g) (d) H2 O(s) ÿ H2 O(g) (b) H2 (R) ÿ H2 (g) (e) H+ (aq) + OH – (aq) ÿ H2 O(R) (c) H2O(R) ÿ H2(g) + 1/2 O2(g) ******** Use the following block outline of the Periodic Table to answer questions 20-26. H O M N R S U V W X P Q Y Z ____ 20. An element exhibits only the +2 oxidation state in its compounds. Which block is it likely to be found in? (a) M ____ 21. (b) N (b) Y (d) V (e) X (b) X (c) M and N (d) M and W (e) M and X (b) 8 (c) 10 (d) 14 (e) 18 The best insulators (non-conductors of both heat and electricity) will be found in block: (a) M ____ 25. (c) S The number of elements in block Y is: (a) 6 ____ 24. (e) X Hydrogen, by virtue of its unique structure and prototypic chemical and physical behavior, is best placed on its own in the Periodic Table. In the form of its +1 and – 1 ions (H+ and H respectively) there is, however, some justification for associating H with block(s): (a) M ____ 23. (d) V An element, M, gives compounds with F, H and O which have the formulae MF4, MH2 and MO3 . Which block will it fall in? (a) N ____ 22. (c) 0 (b) 0 (c) X (d) Y (e) Z An element whose compounds exhibit oxidation states of +6, +5, +4, +3 and +2 would most likely be found in block: (a) 0 (b) R (c) V (d) W (e) X Chem 11500 Test-out Exam Study Guide 12 ____ 26. An element M gives an acidic oxide of formula M2O3. In which block will this element fall? (a) N (b) P (c) M (d) S (e) U ******** Use the following table to answer questions 27 to 30. ____ 27. (a) C(s) + O2(g) ÿ CO2(g) ÄH = – 393.5 kJ (b) H2 (g) + ½ O2(g) ÿ H2O(R) ÄH = – 286 kJ (c) CH4(g) + 2 O2(g) ÿ CO2(g) + 2 H2O(R) ÄH = – 890.4 kJ (d) C(s) ÿ C(g) ÄH = +718.3 kJ (e) H2(g) ÿ 2 HE(g) ÄH = +435 kJ Which is the most exothermic of these reactions? (a) ____ 28. (c) (d) (e) When 1 g of carbon is burned in oxygen: (a) (b) (c) ____ 29. (b) 393.5 kJ are evolved. 393.5 kJ are absorbed. 32.8 kJ are evolved. (d) 32.8 kJ are absorbed. (e) 4724.6 kJ are evolved. For any reaction the ÄH may be equated to the standard heats of formation of the products minus the standard heats of formation of the reactants. Apply this to the third equation above. What then is the ÄH (in kJ) for the following reaction, i.e., the standard heat of formation from its elements of CH4? C(s) + 2 H2(g) ÿ CH4(g) (a) ____ 30. +285.8 (b) – 285.8 (c) Hf (CH4) = _____ +74.9 (d) – 74.9 (e) none of these The average bond energy of the four CH bonds in CH4 is about: 0 (a) 247 kJ (b) 289 kJ (c) 331 kJ (d) 372 kJ (e) 414 kJ ******** ____ 31. 1.936 g of a gas at 120EC and 735 torr occupy a volume of 750 mL. What is the molecular weight of the gas? (a) 86.1 (b) 26.3 (c) 80.4 (d) 48.4 (e) 45.3 Chem 11500 Test-out Exam Study Guide 13 The state mineral of Michigan, known as Perovskite, has an essentially cubic unit cell (of edges ao) as shown in the diagram. [If Indiana has a state mineral it is probably limestone which is not cubic.] At each corner of the unit cell there is a titanium atom, at the center there is a calcium atom, and at the mid-point of each edge there is an oxygen atom. Now answer questions 32-34. ____ 32. Take one of the twelve oxygen atoms at the center of an edge. Between how many unit cells is this atom shared? (a) 2 ____ 33. (b) 4 (d) 8 (e) 12 The empirical (or simplest) formula is related to (in this case identical with) the number of atoms of each kind in the unit cell. The formula for Perovskite is thus: (a) CaTi8O12 ____ 34. (c) 6 (b) CaTiO3 (c) CaTiO (d) CaTi2O3 (e) CaTiO2 Compute the distance of closest approach between a calcium atom and one of its (twelve) oxygen nearest-neighbors: (a) (b) (c) (d) (e) ____ 35. Which of the following is not a member of the same iso-electronic series? (a) 10 Ne (b) 9F – (c) + 11 Na (d) 4 Be 2+ (e) 7N 3– Chem 11500 Test-out Exam Study Guide 14 ____ 36. Arrange the following ions in order of increasing size (smallest first): S2 –, Mg2+, Se2 –, Ca2+ (a) Mg2+ < S2 – < Ca2+ < Se2 – (d) S2 – < Mg2+ < Se2– < Ca2+ (b) Mg2+ < Ca2+ < S2– < Se2 – (e) S2 – < Ca2+ < Mg2+ < Se2 – (c) Mg2+ < S2 – < Se2 – < Ca2+ ____ 37. Which of the following compounds contains the least ionic chemical bonds? (a) KF (b BeF2 (c) KCl (d) BeCl2 (e) BeS ******** Use the following key to answer questions 38-41. (a) n (b) mR (c) p (d) d (e) none of these ____ 38. The quantum number which is the principal determinant of the energy of an electron in an atom. ____ 39. The subshell for which the quantum number, R, has a value of 2. ____ 40. The quantum number which can have a value of –2. ____ 41. The orbital with a spherical shape. ******** ____ 42. How many subshells are contained in the n = 4 shell? (a) ____ 43. 1 (b) 2 (c) 3 (d) 4 (e) 5 (d) 6 (e) 7 How many orbitals are contained in the 4p subshell? (a) 1 (b) 3 (c) 5 Chem 11500 Test-out Exam Study Guide ____ 44. ____ 45. 15 Which of the following orbital diagrams for the ground state of oxygen is incorrect because it violates the Pauli Exclusion Principle? (a) 1s 89 2s 89 2p 89 8 3s 8 (b) 89 89 88 9 9 (c) 89 89 89 8 9 (d) 89 89 8 8 8 (e) 89 89 89 89 8 Which of the following transitions in a hydrogen atom results in the absorption of a photon of the largest energy? (a) n = 1 to m = 2 (d) n = 3 to m = 8 (b) n = 2 to m = 1 (e) n = 8 to m = 3 (c) n = 5 to m = 9 ____ 46. Identify the atomic number of x: (a) (b) (c) ____ 47. 57 145 86 (d) (e) 59 203 P-32, a radioisotope used in leukemia therapy, has a half-life of 14.26 days. What percent of a sample remains after 25 days? (a) (b) (c) 3.37% 25% 30% (d) (e) 35% 50% ***Additional help (problem solving by topic) is available here: http://www.chem.purdue.edu/gchelp/ This is a site with multiple questions on many different topics! Chem 11500 Test-out Exam Study Guide 16 ANSWERS 1. C 26. E 2. C 27. C 3. D 28. C 4. A 29. D 5. D 30. E 6. E 31. A 7. B 32. B 8. D 33. B 9. E 34. A 10. D 35. D 11. A 36. B 12. E 37. E 13. C 38. A 14. B 39. D 15. C 40. B 16. D 41. E 17. E 42. D 18. D 43. B 19. E 44. B 20. B 45. A 21. D 46. D 22. D 47. C 23. D 24. C 25. A