che 1b study guide - the university of texas at austin · this part relates to your knowledge of...

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The University of Texas at Austin, Continuing & Innovative Education K-16 Education Center

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Chemistry 1B Study Guide 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 EA/CBE Study Guide 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: http://ritter.tea.state.tx.us/rules/tac/chapter112/ch112c.html#112.35. 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 EA/CBE. 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 Study Guide 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)

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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.

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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, double-

replacement. • 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.

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• 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. 17.8 g HCl B. 10.5 g HCl C. 23.69 g HCl D. 35.5 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. Na2PO2 C. Na3PO4 D. Na3P2O4

3. Suppose an anesthesiologist used diethyl ether, C4H10O, 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]

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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.

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• 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.


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 10–10 D. 1 x 10–14

2. What is the molarity of 0.375 moles of sulfuric acid, H2SO4, dissolved in 750 mL of distilled water? A. 0.0005 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? NH3 + H2O NH4

+ + OH–

A. NH3 ; OH– B. NH3 ; H2O C. H2O ; NH4

+ D. NH4

+ ; OH–

[1: B; 2: B; 3: C]

!

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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.

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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, C4H10O, 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. 20.2 kJ B. 14.5 kJ C. 905.9 kJ D. 116.18 kJ

3. Why is the following reaction considered spontaneous?

2Li (s) + F2 (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]

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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.


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

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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]

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Chemistry Formula Chart General Formulas

Density =massvolume

! = !!

Percent yield =actual yield

theoretical yield × 100%

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

!lpha particle = ! = 42!"

Energy = Planck!s constant frequency !!!!"!# = ℎ!

Behavior of Gases

The Combined Gas Law: Initial pressure (Initial volume)Initial moles (Initial temperature)

=(Final pressure)(Final volume)(Final moles)(Final temperature)

!!!!!!!!

=!!!!!!!!

Charles’s Law: Initial volume

Initial temperature=

Final volumeFinal temperature

!!!!=!!!!

Ideal Gas Constant:

! = 8.31! × !"#! × !"#

or 0.0821! × !"#! × !"#

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 soluteLiter of solution

! =!"#!

Concentration = amount of substanceVolume of solution

!! = !!!

Molality =number of moles of soluteweight of solvent in kg

m = molkg

pH = −logarithm hydrogen ion concentration pH = −log H!

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Chemistry Formula Chart, continued Conversions

273 K = 0 ℃ 1 mL H!O = 1 g of H!O 1 mol of gas as STP = 22.4 L

cc = cubic centimeter = !"! 101.3 kPa = 1 atmosphere = 760 mm Hg 1 kg = 1000 g

1 meter = 100 centimeters = 1000 millimeters = 1 × 10!micrometer = 1 × 10! nanometers

Electromagnetic Spectrum

speed of light = ! = 3.0 × 10! 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! Ammonium NH!!

Carbonate CO!!! Chlorate CIO!! Chlorite CIO!!

Chromate CrO!!!

Cyanide CN!

Dichromate Cr!O!!! Hydrogen carbonate HCO!! Hydroxide OH! Hypochlorite CIO! Nitrate NO!!

Nitrite NO!! Perchlorate CIO!! Permanganate MnO!!

Phosphate PO!!!

Sulfate SO!!!

Sulfite SO!!!

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che 1b study guide - the university of texas at austin · this part relates to your knowledge of...

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