A.P. Chemistry Practice Test - Ch. 13: Equilibrium .

3y ago
18 Views
2 Downloads
436.15 KB
15 Pages
Last View : 17d ago
Last Download : 2m ago
Upload by : Julia Hutchens
Transcription

A.P. Chemistry Practice Test - Ch. 13: EquilibriumNameMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.1) At equilibrium, .A) the rates of the forward and reverse reactions are equalB) the rate constants of the forward and reverse reactions are equalC) all chemical reactions have ceasedD) the value of the equilibrium constant is 1E) the limiting reagent has been consumed2) Which one of the following will change the value of an equilibrium constant?A) adding other substances that do not react with any of the species involved in the equilibriumB) varying the initial concentrations of reactantsC) changing temperatureD) varying the initial concentrations of productsE) changing the volume of the reaction vessel3) The value of Keq for the following reaction is 0.25:SO2 (g) NO2 (g)SO3 (g) NO (g)The value of Keq at the same temperature for the reaction below is .2SO3 (g) 2NO (g)2SO2 (g) 2NO2 (g)A) 0.062B) 16C) 0.25D) 0.50E) 0.124) The value of Keq for the equilibriumH2 (g) I2 (g)2 HI (g)is 794 at 25eC. At this temperature, what is the value of Keq for the equilibrium below?HI (g)A) 0.0351/2 H2 (g) 1/2 I2 (g)B) 0.0013C) 281D) 397E) 1588

5) The K eq for the equilibrium below is 7.52 10-2 at 480eC.4HCl (g) O2 (g)2Cl2 (g) 2H2O (g)What is the value of K eq at this temperature for the following reaction?2HCl (g) Cl2 (g) H2O (g)A) 0.150B) 0.2741O (g)2 2C) 0.0376D) 5.66 10-3E) 0.0752D) 1.6 10-4E) 776) At 1000 K, the equilibrium constant for the reaction2NO (g) Br2 (g)2NOBr (g)is Kp 0.013. Calculate Kp for the reverse reaction,2NOBr (g)A) 0.992NO (g) Br2 (g).B) 1.1C) 0.0137) The expression for Keq for the reaction below is .4CuO (s) CH4 (g)A)B)C)D)E)CO2 (g) 4Cu (s) 2H2O (g)PCO2 PH2O 2PCH4PCH4PH2O 2 PCO2[Cu] PCO2 PH2O 2[CuO]4 PCH4PCH4PCO2 PH22PCO2 PH2O 2PCuO8) Acetic acid is a weak acid that dissociates into the acetate ion and a proton in aqueous solution:HC2H3O2 (aq)C2H3O2G (aq) H (aq)At equilibrium at 25eC a 0.100 M solution of acetic acid has the following concentrations:[HC2H3O2] 0.0990 M, [C2H3O2G] 1.33 10-3 M, and [H ] 1.33 10-3 M. The equilibrium constant, Keq ,for the ionization of acetic acid at 25eC is .A) 5.71 104B) 1.79 10-5C) 1.75 10-72D) 5.71 106E) 0.100

9) At 200eC, the equilibrium constant for the reaction below is 2.40 103.2NO (g)N2 (g) O2 (g)A closed vessel is charged with 36.1 atm of NO. At equilibrium, the partial pressure of O2 is atm.A) 35.7C) 1.50 10-2B) 18.1D) 6.00E) 29410) How is the reaction quotient used to determine whether a system is at equilibrium?A) The reaction is at equilibrium when Q Keq .B) The reaction is at equilibrium when Q Keq .C) At equilibrium, the reaction quotient is undefined.D) The reaction quotient must be satisfied for equilibrium to be achieved.E) The reaction is at equilibrium when Q Keq .11) In the coal-gasification process, carbon monoxide is converted to carbon dioxide via the following reaction:CO2 (g) H2 (g)CO (g) H2O (g)In an experiment, 0.35 mol of CO and 0.40 mol of H2O were placed in a 1.00-L reaction vessel. At equilibrium,there were 0.19 mol of CO remaining. Keq at the temperature of the experiment is .A) 0.75B) 1.0C) 5.47D) 1.78E) 0.5612) Nitrosyl bromide decomposes according to the following equation.2NO (g) Br2 (g)2NOBr (g)A sample of NOBr (0.64 mol) was placed in a 1.00-L flask containing no NO or Br2. At equilibrium the flaskcontained 0.46 mol of NOBr. How many moles of NO and Br2, respectively, are in the flask at equilibrium?A) 0.46, 0.23B) 0.18, 0.090C) 0.46, 0.46D) 0.18, 0.360E) 0.18, 0.1813) In which of the following reactions would increasing pressure at constant temperature not change the telier's principle?concentrations of reactants and products, based on Le ChaA) N2 (g) 3H2 (g)2NH3 (g)B) 2N2 (g) O2 (g)2N2O (g)C) N2 (g) 2O2 (g)2NO2 (g)D) N2O4 (g)E) N2 (g) O2 (g)2NO2 (g)2NO (g)3

14) Consider the following reaction at equilibrium:2CO2 (g)2CO (g) O2 (g)DHe -514 kJ telier's principle predicts that adding O2 (g) to the reaction container will .Le ChaA) decrease the partial pressure of CO2 (g) at equilibriumB) decrease the value of the equilibrium constantC) increase the partial pressure of CO2 (g) at equilibriumD) increase the value of the equilibrium constantE) increase the partial pressure of CO (g) at equilibrium15) Consider the following reaction at equilibrium:2CO2 (g)2CO (g) O2 (g)DHe -514 kJ telier's principle predicts that an increase in temperature will .Le ChaA) increase the partial pressure of O2 (g)B) decrease the value of the equilibrium constantC) increase the partial pressure of COD) decrease the partial pressure of CO2 (g)E) increase the value of the equilibrium constant16) Consider the following reaction at equilibrium.2CO2 (g)2CO (g) O2 (g)DHe -514 kJ telier's principle predicts that the equilibrium partial pressure of CO (g) can be maximized by carryingLe Chaout the reaction .A) at high temperature and high pressureB) at high temperature and low pressureC) at low temperature and low pressureD) at low temperature and high pressureE) in the presence of solid carbon17) The effect of a catalyst on an equilibrium is to .A) increase the rate at which equilibrium is achieved without changing the composition of the equilibriummixtureB) increase the rate of the forward reaction onlyC) shift the equilibrium to the rightD) increase the equilibrium constant so that products are favoredE) slow the reverse reaction only4

18) The following equilibrium is readily established:SO2Cl2 (g) SO2 (g) Cl2 (g)At equilibrium at 373 K, a 1.00-L reaction vessel contains 0.0106 mol of SO2Cl2 and 0.0287 mol each of SO2 andCl2. What is Keq for the reaction at 373 K?A) 12.8B) 2.72C) 0.0781D) 2.39E) 0.41819) Dinitrogentetraoxide partially decomposes according to the following equilibrium:N2O4 (g) 2NO 2 (g)A 1.000-L flask is charged with 3.00 10-2 mol of N2O4. At equilibrium, 2.36 10-2 mol of N2O4 remains.Keq for this reaction is .A) 0.723B) 1.92 10-4C) 6.93 10-3D) 0.391E) 0.21220) The Keq for the reation below is 1.49 108 at 100e C:CO (g) Cl2 (g) COCl2 (g)In an equilibrium mixture of the three gases, PCO PCl2 8.60 10-4 atm. The partial pressure of the product,phosgene (COCl2), is atm.A) 2.01 1014B) 1.72 1011C) 1.28 105D) 4.96 10-15E) 1.10 10221) Phosphorous trichloride and phosphorous pentachloride equilibrate in the presence of molecular chlorineaccording to the reaction:PCl3 (g) Cl2 (g) PCl5 (g)Keq 2.01 at 500 K. A 1.000-L reaction vessel is charged with 0.990 mol of PCl5 and allowed to equilibrate atthis temperature. The equilibrium partial pressure of PCl3 is atm.A) 0.702B) 4.25C) 4.50D) 36.4E) 0.49622) Phosphorous trichloride and phosphorous pentachloride equilibrate in the presence of molecular chlorineaccording to the reaction:PCl3 (g) Cl2 (g) PCl5 (g)Keq 2.01 at 500 K. A 1.000-L reaction vessel is charged with 0.300 mol of PCl5 and allowed to equilibrate atthis temperature. The equilibrium partial pressure of PCl5 is atm.A) 10.1B) 0.386C) 2.245D) 2.48E) 0.211

2004 Free Response – Form B1.N2(g) 3 H2(g) x 2 NH3(g)For the reaction represented above, the value of the equilibrium constant, Kp is 3.1 10-4at 700 K.a)Write the expression for the equilibrium constant, Kp, for the reaction.b)Assume that the initial partial pressures of the gases are as follows:P(N2) 0.411 atm, P(H2) 0.903 atm, and P(NH3) 0.224 atm.i)Calculate the value of the reaction quotient, Q, at these initial conditions.ii)Predict the direction in which the reaction will proceed at 700. K if the initialpartial pressures are those given above. Justify your answer.c)Calculate the value of the equilibrium constant, Kc, given that the value of Kp for thereaction at 700. K is 3.1 10-4.d)The value of Kp for the reaction represented below is 8.3 10-3 at 700. K.NH3(g) H2S(g) x NH4HS(g)Calculate the value of Kp at 700. K for each of the reactions represented below.i)NH4HS(g) x NH3(g) H2S(g)ii)2 H2S(g) N2(g) 3 H2(g) x 2 NH4HS(g)

Answer KeyTestname: CH 13 PRAC TEST EQUILIBRIUM.TSTMULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.1) AID: chem9b 15.1-12) CID: chem9b 15.1-73) AID: chem9b 15.1-124) AID: chem9b 15.1-155) BID: chem9b 15.1-186) EID: chem9b 15.1-247) AID: chem9b 15.1-278) BID: chem9b 15.1-319) BID: chem9b 15.1-3510) EID: chem9b 15.1-3811) EID: chem9b 15.1-3912) BID: chem9b 15.1-4213) EID: chem9b 15.1-4714) CID: chem9b 15.1-5015) BID: chem9b 15.1-5116) CID: chem9b 15.1-5217) AID: chem9b 15.1-5418) DID: chem9b 15.2-219) CID: chem9b 15.2-320) EID: chem9b 15.2-421) BID: chem9b 15.2-81

Answer KeyTestname: CH 13 PRAC TEST EQUILIBRIUM.TST22) AID: chem9b 15.2-92

AP CHEMISTRY2004 SCORING GUIDELINES (Form B)Question 1 2 NH (g)N2(g) 3 H2(g) 31. For the reaction represented above, the value of the equilibrium constant, Kp , is 3.1 10 – 4 at 700. K.(a) Write the expression for the equilibrium constant, Kp , for the reaction.Kp p 2 NH31 point for pressure expression1 point for correct substitutionpN 2 p 3H 2(b) Assume that the initial partial pressures of the gases are as follows:pN 0.411 atm, pH 0.903 atm, and pNH 0.224 atm.223(i) Calculate the value of the reaction quotient, Q, at these initial conditions.Q p 2 NH3pN 2 p 3H 2 (0.224) 2(0.411)(0.903)31 point for calculation of Q with correct mass action expressionNote: must be consistent with part (a)Q 0.166(ii) Predict the direction in which the reaction will proceed at 700. K if the initial partial pressures arethose given above. Justify your answer.Since Q Kp , the numerator must decrease and thedenominator must increase, so the reaction mustproceed from right to left to establish equilibrium.1 point for direction or for stating that Q Kp1 point for explanation(c) Calculate the value of the equilibrium constant, Kc , given that the value of Kp for the reaction at 700. Kis 3.1 10 – 4.Kp Kc(RT) n n 2 – 4 2Kp Kc(RT) 23.1 10 4 Kc(0.08211 point for calculating nL atm 700 K) 2mol K3.1 10 4 Kc(57.5) 21 point for correct substitution and value of Kc3.1 10 4 Kc(3.0 10 4)1.0 KcCopyright 2004 by College Entrance Examination Board. All rights reserved.Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for AP students and parents).2

AP CHEMISTRY2004 SCORING GUIDELINES (Form B)Question 1 (cont’d.)(d) The value of Kp for the reaction represented below is 8.3 10 –3 at 700. K. NH HS(g)NH3(g) H2S(g) 4Calculate the value of Kp at 700. K for each of the reactions represented below. NH (g) H S(g)(i) NH4HS(g) 32Kp 18.3 10 3 1.2 1021 point for the calculation of Kp 2 NH HS(g)(ii) 2 H2S(g) N2(g) 3 H2(g) 4 NH HS(g)]2 [NH3(g) H2S(g) 4 2 NH (g)N (g) 3 H (g) 223Kp (8.3 10 3)2Kp 3.1 10 4 2 NH HS(g)2 H2S(g) N2(g) 3 H2(g) 4Kp (8.3 10 3)2 (3.1 10 4) 2.1 10 81 point for squaring Kp for NH4HS or formultiplying Kp’s1 point for correct KpCopyright 2004 by College Entrance Examination Board. All rights reserved.Visit apcentral.collegeboard.com (for AP professionals) and www.collegeboard.com/apstudents (for AP students and parents).3

2004 Free Response – Form B 1. N2(g) 3 H2(g) x 2 NH3(g) For the reaction represented above, the value of the equilibrium constant, Kp is 3.1 10-4 at 700 K. a) Write the expression for the equilibrium constant, Kp, for the reaction. b) Assume that the initial partial pressures of the gases are as follows:

Related Documents:

Chemistry ORU CH 210 Organic Chemistry I CHE 211 1,3 Chemistry OSU-OKC CH 210 Organic Chemistry I CHEM 2055 1,3,5 Chemistry OU CH 210 Organic Chemistry I CHEM 3064 1 Chemistry RCC CH 210 Organic Chemistry I CHEM 2115 1,3,5 Chemistry RSC CH 210 Organic Chemistry I CHEM 2103 1,3 Chemistry RSC CH 210 Organic Chemistry I CHEM 2112 1,3

Physical chemistry: Equilibria Physical chemistry: Reaction kinetics Inorganic chemistry: The Periodic Table: chemical periodicity Inorganic chemistry: Group 2 Inorganic chemistry: Group 17 Inorganic chemistry: An introduction to the chemistry of transition elements Inorganic chemistry: Nitrogen and sulfur Organic chemistry: Introductory topics

Accelerated Chemistry I and Accelerated Chemistry Lab I and Accelerated Chemistry II and Accelerated Chemistry Lab II (preferred sequence) CHEM 102 & CHEM 103 & CHEM 104 & CHEM 105 General Chemistry I and General Chemistry Lab I and General Chemistry II and General Chemistry Lab II (with advisor approval) Organic chemistry, select from: 9-10

CHEM 0350 Organic Chemistry 1 CHEM 0360 Organic Chemistry 1 CHEM 0500 Inorganic Chemistry 1 CHEM 1140 Physical Chemistry: Quantum Chemistry 1 1 . Chemistry at Brown equivalent or greater in scope and scale to work the studen

Chemistry is the science that describes matter, its properties, the changes it undergoes, and the energy changes that accompany those processes. Inorganic chemistry Organic chemistry Physical chemistry Biochemistry Applied Chemistry: Analytical chemistry, Pharmaceutical Chemistry, . Istv an Szalai (E otv os University) Lecture 1 6 / 45

Chemistry of Cycloalkanes 13. Chemistry of Alkyl halides 14. Alcohols 15. Chemistry of Ethers and Epoxides 16. Chemistry of Benzene and Aromaticity 17. Chemistry of Aryl Halides 18. Aromatic Sulphonic Acids 19. Chemistry of Aldehydes and Ketones 20. Carboxylic Acids 21. Chemistry of Carboxylic Acid Derivativ

ADVANCED DIPLOMA Diploma in Chemistry 60% in Analytical Chemistry 3 Theory & Practical, Chemical Quality Assurance, Mathematics 2 Chemical Industrial 1 or S5 Subjects and Chemistry project II. Semester 1 Analytical Chemistry IV Physical Chemistry IV Research Methodology in Chemistry Semester 2 Inorganic Chemistry IV Organic Chemistry IV .

chemistry unit 5 the mole answer key, chemistry matters unit 6d mole to mass calculations answers, unit 5 the mole and stoichiometry chemistry sv 0424-7 answers, chemistry unit 5 the mole answers, chemistry unit 8 worksheet 1 mole relationships answers, chemistry semester 2 review unit 9 the mole answers, chemistry