Chemistry 1B Study Guide Examination for Acceleration (EA)/Credit by Exam (CBE)

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120513 Chemistry 1B Examination for Acceleration (EA)/Credit by Exam (CBE) The exam you are interested in taking is designed to test your proficiency in the relevant subject matter.

1 Chemistry 1B Examination for Acceleration (EA)/Credit by Exam (CBE) The exam you are interested in taking is designed to test your proficiency in the relevant subject matter. You should be thoroughly familiar with the subject matter before you attempt to take the exam. This can help you prepare for the exam by giving you an idea of what you need to review. You can check your familiarity level by reviewing the Texas Essential Knowledge and Skills (TEKS) for this course (see below). To refine your skills, you can refer to any of the state-adopted textbooks. Texas Essential Knowledge and Skills (TEKS) Every question that appears on this exam is derived from the knowledge and skills statements and student expectations within the Texas-mandated standards, the Texas Essential Knowledge and Skills (TEKS). You can view the TEKS for this exam online via the following link: Refer to section (c), Knowledge and skills, 1A 12C. Throughout this guide, you ll see TEKS references. These refer to the numbers listed under (c) Knowledge and skills; for example, 1A or 3B. Note: Coverage of the TEKS is split between Chemistry 1A and 1B; so those TEKS not covered in this exam are covered in the Chemistry 1A. Materials Needed You will need to bring a #2 pencil to complete the exam. You are also allowed to bring and use a graphing calculator. You will receive a computer-graded answer sheet when you arrive at the testing center. You will be provided a formula sheet and periodic table with your exam. The formula sheet and periodic table are also included at the end of this for your review. Exam Structure You will be allowed 3 hours to complete this exam. The exam consists of 50 multiple-choice questions worth 2 points each for a total of 100 points. The exam consists of the following 4 parts: Part 1: Moles and Stoichiometry (15 questions) Part 2: Solutions (~15 questions) Part 3: Energy (~12 questions) Part 4: Radiation and Reactions (8 questions) 1

2 Scholastic Honesty When you arrive at the testing center, you will be asked to carefully read the exam rules and sign a statement agreeing to take the exam in accordance with the rules. This is called the Examinee s Certification. The following is a copy of these rules: Examinee s Certification This certification must be signed before the exam is administered and then returned with the completed examination attached, or credit for the exam will not be given. Scholastic dishonesty is a serious academic violation that will not be tolerated. Scholastic dishonesty encompasses, but is not limited to: copying from another student s work; using an unauthorized testing proctor or taking the exam at an unauthorized testing location; using materials not authorized by a testing proctor; possessing materials that are not authorized by a testing proctor, such as lessons, books, or notes; knowingly using or soliciting, in whole or part, the contents of an unadministered test; collaborating with or seeking aid from another student without authorization during the test; substituting for another person, or permitting another person to substitute for oneself, in taking a course test or completing any course-related assignment; using, buying, stealing, or transporting some or all of the contents of an unadministered test, test rubric, homework answer, or computer program. Evidence of scholastic dishonesty will result in a grade of F on the examination and an F in the course (if applicable). At the testing center, you will be asked to sign a statement that says you have read the above and agree to complete the examination with scholastic honesty. 2

3 General Study Tips The bulleted lists and sample questions in this study guide can assist you in preparing for the exam. It is a fairly complete guide, but does not cover every item on the test. Ultimately, you should use the TEKS to guide your exam preparation. Additional Study Tips The following information provides direction for your studies. For each part, you will find study tips and sample questions to give you a general idea of the types of questions you can expect to see on the exam. Part 1: Moles and Stoichiometry This part relates to your knowledge of chemical reactions, the behavior of gases, and stoichiometry. The exam includes 15 questions, each worth 2 points, related to this topic. Study Tips for Part 1 This part relates to TEKS 8A 9C. Familiarize yourself with those TEKS, and then be prepared to demonstrate knowledge of the following topics: Chemical Reactions Apply the law of conservation of mass to interpret the results of a chemical reaction. Write and understand chemical equations, word equations and formula equations. Write a formula equation from a word equation. Balance a chemical equation. Interpret a balanced chemical equation. Identify types of chemical reactions; e.g., combustion, single-replacement, doublereplacement. Predict the reactants or products of a chemical reaction. Understand the importance of classifying chemical reactions. Be able to identify theoretical and percent yields of chemical equations. Behavior of Gases Explain the four main factors that affect the behavior of a gas. Know the formal mathematical expressions that define relationships between the pressure, volume, temperature, and moles of a gas. Calculate the pressure, volume, temperature, and number of moles of a gas. Calculate the total pressure and partial pressures of a mixture of gases. Calculate the partial pressure of gases from the number of moles of these gases. Apply Boyle s law to determine the relationship between gas molecules. Stoichiometry Convert from molecules or atoms to moles, and moles to molecules or atoms. Calculate the molar mass of a compound. Convert from moles to mass and mass to moles. Calculate the percent composition of a compound. 3

4 Know the difference between the empirical and molecular formulas of a compound. Calculate the empirical and molecular formulas of a compound. Describe the concept of the mole and identify the numerical value of the mole. Use Avogadro s number to calculate the number of molecules in a sample. Perform stoichiometric calculations to complete various conversions. Write mole ratios. Use mole-to-mole conversions to predict the limiting reagent of a reaction. Determine the efficiency of a chemical reaction by doing mass-to-mass conversions and calculating the percent yield. Understand why percent yield is useful. Sample Questions for Part 1 The following are sample questions. You can find the correct answers listed after the questions, but try answering the questions without looking at the answers first to check your comprehension. DIRECTIONS: Select the BEST response to each of the following questions. 1. How many grams of hydrochloric acid, HCl, are needed to make a 1.3 mole solution in 500 ml of water? Molarity = moles/liter A g HCl B g HCl C g HCl D g HCl 2. A sample contains 84.0 g sodium, 37.8 g phosphorous, and 77.8 g oxygen. What is the empirical formula? A. NaPO B. Na 2 PO 2 C. Na 3 PO 4 D. Na 3 P 2 O 4 3. Suppose an anesthesiologist used diethyl ether, C 4 H 10 O, as a general anesthetic in the past. If 0.68 moles of ether occupy 3.7 L of a cylinder, calculate what volume the gas will occupy if the moles increase to 0.9 moles. A. 2.3 L B. 2.5 L C. 4.9 L D. 5.5 L [1: C; 2: A; 3: C] 4

5 Part 2: Solutions This part relates to your knowledge of hydrogen bonding and water, properties of solutions, and acids and bases. The exam includes about 15 questions, each worth 2 points, related to this topic. Study Tips for Part 2 This part relates to TEKS 10A 10J. Familiarize yourself with those TEKS, and then be prepared to demonstrate knowledge of the following topics: Water Understand hydrogen bonding and how it contributes to the physical characteristics of water. Be familiar with water s role in chemical and biological systems. Discuss the role that hydrogen bonds play in determining the structure of ice crystals and why ice is less dense than liquid water. Explain how water behaves as a solvent. Explain why like dissolves like. Chemical bonds and how they impact solutions; e.g., polar, non-polar, ionic, covalent, and hydrogen. Properties of Solutions Calculate the molar mass of elements and compounds. Calculate the number of moles of solute from the concentration of a solution. Express the concentration of a solution in percent by mass, molarity, and molality. Explain the factors that affect solubility; i.e., temperature, pressure, and polarity. Interpret a solubility vs. temperature graph to determine whether a solution is unsaturated, saturated, or supersaturated. Explain the effect that adding a solute has on the boiling point and freezing point of water. Discuss the relationship between the solubility of a gas and the temperature of a solution. Explain how non-polar gases are kept in solution in a polar solvent. Identify electrolytes and nonelectrolytes. Understand the impact of density and viscosity on a solution. Acids and Bases Recognize the general properties of both acids and bases. Know why acids and bases have the structures they have. Write the correct chemical formulas and names for acids and bases. Define and identify Arrehnius, Brønsted-Lowry, and Lewis acids and bases. Describe acid base reactions that form water. Recognize neutral ph and the color litmus paper will turn in the presence of an acid. Know the relationships between H +, OH, poh, and ph and how to calculate each. Describe why it is dissociation, not concentration, that causes an acid to be strong or weak. 5

6 Identify dissociation degrees for strong and weak acids and bases. Write and identify the conjugate base of an acid and the conjugate acid of a base. Identify acid base neutralization reactions. Write the correct chemical formulas for the products of acid base neutralization reactions. Write the equilibrium reaction for acid base neutralization reactions. Predict and calculate the ph of a solution after a neutralization reaction is completed. Use hydrogen and hydroxide ion concentrations to calculate ph. Understand reduction half-reactions. Sample Questions for Part 2 The following are sample questions. You can find the correct answers listed after the questions, but try answering the questions without looking at the answers first to check your comprehension. DIRECTIONS: Select the BEST response to each of the following questions. 1. What is the [H + ] of a solution with a ph of 4? A. 1 x 10 2 B. 1 x 10 4 C. 1 x D. 1 x What is the molarity of moles of sulfuric acid, H 2 SO 4, dissolved in 750 ml of distilled water? A mol/l B. 0.5 mol/l C. 1.5 mol/l D. 281 mol/l 3. In the following equation, which molecules are acids? NH 3 + H 2 O! NH OH A. NH 3 ; OH B. NH 3 ; H 2 O C. H 2 O ; NH 4 + D. NH 4 + ; OH [1: B; 2: B; 3: C] 6

7 Part 3: Energy This part relates to your knowledge of energy and states of matter. The exam includes about 12 questions, each worth 2 points, related to this topic. Study Tips for Part 3 This part relates to TEKS 11A 11E. Familiarize yourself with those TEKS, and then be prepared to demonstrate knowledge of the following topics: Thermochemistry Define energy and its forms. Define and recognize applications of enthalpy. Define entropy and spontaneous reactions. Determine the direction of heat flow in a system. Identify whether a system has potential or kinetic energy. Explain the relationship between energy, heat, and work. Calculate the amount of energy converted into heat and the amount converted into work. Identify a reaction as endothermic or exothermic. Understand the law of conservation of energy. Calculate the specific heat capacity of a substance. Calculate the change in temperature of a substance using its specific heat. Use calorimetric calculations to calculate the heat of a chemical process. Use Hess s Law to manipulate chemical equations and calculate enthalpy changes. Understand the concept of molar heat of formation, and use it to calculate enthalpy change in a reaction. Determine the change in entropy of a chemical reaction. Calculate the change in free energy for a reaction. Predict whether a reaction will proceed spontaneously. States of Matter Interpret and extrapolate information from a graph of the boiling points of different substances and information from a phase diagram. Understand the concept of the triple point and the critical point in a phase diagram. Understand the relationship between melting point, boiling point, and freezing point of a pure substance. 7

8 Sample Questions for Part 3 The following are sample questions. You can find the correct answers listed after the questions, but try answering the questions without looking at the answers first to check your comprehension. DIRECTIONS: Select the BEST response to each of the following questions. 1. If the temperature of a substance goes above the critical point as measured on a phase diagram, what will happen to the substance? A. Sublimation will occur. B. It will exist at all three states: gas, liquid, and solid. C. It will exist in a state where the gas and liquid states cannot be distinguished. D. The scenario is impossible because the temperature of a substance cannot rise above the critical point. 2. How much heat is absorbed by diethyl ether, C 4 H 10 O, when 57.7 grams evaporate? (Diethyl ether has a heat of fusion of 6.90 kj/mol and a heat of vaporization of 26.0 kj/mol.) A kj B kj C kj D kj 3. Why is the following reaction considered spontaneous? 2Li (s) + F 2 (g) 2LiF (s) A. Because it is a redox reaction. B. Because its cell potential is positive. C. Because it is a reduction-only reaction. D. Because the cell potential is less than 10. [1: C; 2: A; 3: B] 8

9 Part 4: Radiation and Reactions This part relates to your knowledge of radiation and reactions. The exam includes 8 questions, each worth 2 points, related to this topic. Study Tips for Part 4 This part relates to TEKS 12A 12C. Familiarize yourself with those TEKS, and then be prepared to demonstrate knowledge of the following topics: Explain radioactive decay and what makes isotopes stable or unstable. Write nuclear equations. Know the different types of radioactive decay; i.e., alpha, beta, and gamma. Understand the difference between fission and fusion reactions. Explain a nuclear fission chain reaction and the concept of critical mass. Understand the concept of half-life and how to calculate radioactive decay. Identify radioactive elements. Identity different uses for radioactive materials. Identify safety concerns that are considered before building a nuclear power plant. Describe how nuclear waste is produced and how we dispose of these materials. Sample Questions for Part 4 The following are sample questions. You can find the correct answers listed after the questions, but try answering the questions without looking at the answers first to check your comprehension. DIRECTIONS: Select the BEST response to each of the following questions. 1. An alpha particle is. A. identical to a helium nucleus B. formed during nuclear fission C. emitted during gamma radiation D. composed of a proton and a neutron 2. What type of nuclear reaction is represented by the following equation?!!"!!!!!!ra!" Rn +! He A. Beta decay B. Alpha decay C. Gamma radiation D. Neutron absorption 9

10 3. Below is a half-life chart showing the percentage of original U-235 remaining over time. Based upon the chart, how much of an original 500 g sample of uranium would remain after 800 million years? A. 45 grams B. 55 grams C. 225 grams D. 450 grams [1: A; 2: B; 3: C] 10

11 CHE 1B & Chemistry Formula Chart General Formulas Density = mass!! = volume! Percent yield = actual yield 100% theoretical yield Pressure Volume = moles! Temperature!" =!"# Heat = mass specific heat constant change in Kelvin! =!"! Velocity = frequency wavelength! =!" Atomic Structure ℎ = Planck! s constant = 6.63 x 10!!" J s amu = atomic mass unit Energy = Planck! s constant frequency!!!!"!# = ℎ! 4!lpha particle =! =!" 2 Behavior of Gases The Combined Gas Law: Initial pressure (Initial volume) (Final pressure)(final volume)!!!!!!!! = = Initial moles (Initial temperature) (Final moles)(final temperature)!!!!!!!! Charles s Law: Initial volume Final volume!!!! = = Initial temperature Final temperature!!!! Ideal Gas Constant:!!"#!!"#! = 8.31 or !!"#!!"# Specific Heat Values for the States of Water Ice = 2090 J/kg C Water = 4186 J/kg C Steam = 2010 J kg C Thermochemistry Heat gained or lost = mass specific heat Change in temperature! =!"! Solutions Molarity = moles of solute!"# amount of substance!!! = Concentration =!! = Liter of solution! Volume of solution! number of moles of solute mol Molality = m = weight of solvent in kg kg ph = logarithm hydrogen ion concentration ph = log H! 11

CHE 1B 33424 & 43424 Chemistry Formula Chart, continued Conversions 273 K = 0 1 ml H! O = 1 g of H! O cc = cubic centimeter =!"! 1 mol of gas as STP = 22.4 L 101.

12 CHE 1B & Chemistry Formula Chart, continued Conversions 273 K = 0 1 ml H! O = 1 g of H! O cc = cubic centimeter =!"! 1 mol of gas as STP = 22.4 L kpa = 1 atmosphere = 760 mm Hg 1 kg = 1000 g 1 meter = 100 centimeters = 1000 millimeters = 1 10! micrometer = 1 10nanometers Electromagnetic Spectrum speed of light =! = m/s wave speed = wavelength frequency! =!" Gamma rays X-rays UV light Visible light Microwaves Radio/TV waves Visible Light Polyatomic Ions Acetate! C! H! O!!, CH! COO Cyanide CN Nitrite NO! Ammonium NH! Dichromate Cr! O!! Perchlorate CIO! Carbonate CO!! Hydrogen carbonate HCO! Permanganate MnO! Chlorate CIO! Hydroxide OH Phosphate PO!! Chlorite CIO! Hypochlorite CIO Sulfate SO!! Chromate CrO!! Nitrate NO! Sulfite SO!! 12

13 13 CHE 1B & 43424

Chemistry A. Introduction to Chemistry be familiar with the five branches of chemistry; discuss the scientific method.

Chemistry A. Introduction to Chemistry be familiar with the five branches of chemistry; discuss the scientific method. Chemistry A Credit by Exam This can help you prepare for the exam by giving you an idea of what you need to study, review, and learn. To succeed, you should be thoroughly familiar with the subject matter