Physics section test (7)

MCAT Section Tests Dear Future Doctor, The following Section Test and explanations should be used to practice and to assess your mastery of critical thinking in each of the section areas Topics are confluent and are not necessarily in any specific order or fixed proportion This is the level of integration in your preparation that collects what you have learned in the Kaplan classroom and synthesizes your knowledge with your critical thinking Simply completing the tests is inadequate; a solid understanding of your performance through your Score Reports and the explanations is necessary to diagnose your specific weaknesses and address them before Test Day All rights are reserved pursuant to the copyright laws and the contract clause in your enrollment agreement and as printed below Misdemeanor and felony infractions can severely limit your ability to be accepted to a medical program and a conviction can result in the removal of a medical license We offer this material for your practice in your own home as a courtesy and privilege Practice today so that you can perform on test day; this material was designed to give you every advantage on the MCAT and we wish you the best of luck in your preparation Sincerely, Albert Chen Executive Director, Pre-Health Research and Development Kaplan Test Prep © 2003 Kaplan, Inc All rights reserved No part of this book may be reproduced in any form, by Photostat, microfilm, xerography or any other means, or incorporated into any information retrieval system, electronic or mechanical without the written permission of Kaplan, Inc This book may not be duplicated, distributed or resold, pursuant to the terms of your Kaplan Enrollment Agreement Physical Sciences Test Time: 35 Minutes Number of Questions: 27 MCAT PHYSICAL SCIENCES DIRECTIONS: Most of the questions in the following Physical Sciences test are organized into groups, with a descriptive passage preceding each group of questions Study the passage, then select the single best answer to each question in the group Some of the questions are not based on a descriptive passage; you must also select the best answer to these questions If you are unsure of the best answer, eliminate the choices that you know are incorrect, then select an answer from the choices that remain Indicate your selection by blackening the corresponding circle on your answer sheet A periodic table is provided below for your use with the questions PERIODIC TABLE OF THE ELEMENTS H 1.0 He 4.0 Li 6.9 Be 9.0 B 10.8 C 12.0 N 14.0 O 16.0 F 19.0 10 Ne 20.2 11 Na 23.0 12 Mg 24.3 13 Al 27.0 14 Si 28.1 15 P 31.0 16 S 32.1 17 Cl 35.5 18 Ar 39.9 19 K 39.1 20 Ca 40.1 21 Sc 45.0 22 Ti 47.9 23 V 50.9 24 Cr 52.0 25 Mn 54.9 26 Fe 55.8 27 Co 58.9 28 Ni 58.7 29 Cu 63.5 30 Zn 65.4 31 Ga 69.7 32 Ge 72.6 33 As 74.9 34 Se 79.0 35 Br 79.9 36 Kr 83.8 37 Rb 85.5 38 Sr 87.6 39 Y 88.9 40 Zr 91.2 41 Nb 92.9 42 Mo 95.9 43 Tc (98) 44 Ru 101.1 45 Rh 102.9 46 Pd 106.4 47 Ag 107.9 48 Cd 112.4 49 In 114.8 50 Sn 118.7 51 Sb 121.8 52 Te 127.6 53 I 126.9 54 Xe 131.3 55 Cs 132.9 56 Ba 137.3 57 La * 138.9 72 Hf 178.5 73 Ta 180.9 74 W 183.9 75 Re 186.2 76 Os 190.2 77 Ir 192.2 78 Pt 195.1 79 Au 197.0 80 Hg 200.6 81 Tl 204.4 82 Pb 207.2 83 Bi 209.0 84 Po (209) 85 At (210) 86 Rn (222) 87 Fr (223) 88 Ra 226.0 89 Ac † 227.0 104 Unq (261) 105 Unp (262) 106 Unh (263) 107 Uns (262) 108 Uno (265) 109 Une (267) * 58 Ce 140.1 59 Pr 140.9 60 Nd 144.2 61 Pm (145) 62 Sm 150.4 63 Eu 152.0 64 Gd 157.3 65 Tb 158.9 66 Dy 162.5 67 Ho 164.9 68 Er 167.3 69 Tm 168.9 70 Yb 173.0 71 Lu 175.0 † 90 Th 232.0 91 Pa (231) 92 U 238.0 93 Np (237) 94 Pu (244) 95 Am (243) 96 Cm (247) 97 Bk (247) 98 Cf (251) 99 Es (252) 100 Fm (257) 101 Md (258) 102 No (259) 103 Lr (260) GO ON TO THE NEXT PAGE as developed by Physical Sciences Passage I (Questions 1–5) When light enters the eye, it forms an image on the retina First, light from the object passes through the cornea, a converging lens within the eye, and then through a liquid known as the aqueous humor After this it passes through a second crystalline converging lens into the eyeball, which is filled with a fluid known as the vitreous humor The light is refracted by the cornea and by the crystalline lens, and is focused on the retina, which transmits electrical impulses along the optic nerve to the brain The index of refraction of the vitreous humor is greater than the index of refraction of the aqueous humor which is greater than the index of refraction of air What is the relationship of the speed of light in each of these media? A fastest in air, slower in aqueous humor, slowest in vitreous humor B fastest in vitreous humor, slower in aqueous humor, slowest in air C equal in all three D depends on the index of refraction of the lenses which separate the media In myopia, or nearsightedness, the light converges too soon, causing the image of an object at infinity to be focused before the retina Which of the following offers a plausible explanation of the underlying reason for myopia? A The ciliary muscle cannot tense up sufficiently B The ciliary muscle cannot relax sufficiently C The aqueous humor absorbs too much light D The aqueous humor does not absorb enough light The cornea has a constant focal length, and is responsible for most of the refraction of the light from the object The crystalline lens has a variable focal length, which enables the eye to focus the image on the retina, even though the object distance varies The focal length of the crystalline lens is varied by tensing and relaxing the ciliary muscle that surrounds the lens It is relaxed when focusing on a distant object, and tensed when focusing on a near object It is important to note that when the ciliary muscle is tensed, the lens assumes a more spherical shape, thus decreasing the focal length The cornea and the crystalline lens may be considered two thin lenses in contact, and therefore thought of as a single converging lens at a distance of 2.0 centimeters from the retina When an object is at an infinite distance away, the focal length of the lens is equal to the distance between the lens and the retina When the distance to the object is appreciably smaller, the focal length of the lens changes so that the image is still focused on the retina Hyperopia, or farsightedness, is caused when an object at infinity is focused behind the retina In order to correct hyperopia, which of the following lens types would be the most appropriate? A C B D GO ON TO THE NEXT PAGE KAPLAN MCAT A myopic person’s eye has a relaxed focal length of 1.9 cm What is the maximum distance from the eye at which she can see an object clearly, and what is the magnification of the lens for an object at this point? A O = cm, m = B O = 38 cm, m = - C O = 38 cm, m = - D O = 50 cm, m = - 38 19 A B C D I only I and II only II and III only I, II, and III A mixture of two volatile solvents that exhibits ideal behavior will boil when the total vapor pressure is equal to the atmospheric pressure The concentration of the more volatile component will always be greater in the vapor than in the solution If the vapor above the boiling mixture is condensed and boiled again, it will be even richer in the more volatile component With successive condensations and boilings, it is possible to separate the individual components This process is known as fractional distillation 50 Which of the following is true of the image formed on the retina? I It is real II It is inverted III It is reduced Passage II (Question 6–11) There are, however, a number of solvent systems that not behave ideally, and consequently cannot be separated Figure shows a boiling-point diagram for a system that is called a minimum-boiling azeotrope In a system such as this, the attraction between unlike molecules is weaker than the attraction between like molecules; as a result, the solution boils at a lower temperature than the pure components Systems that have a maximum on the boiling-point diagram are called maximum-boiling azeotropes Fractional distillation of these non-ideal systems will, at best, give one pure component and the azeotrope GO ON TO THE NEXT PAGE as developed by Physical Sciences Which of the following best describes the mechanism by which two substances form a maximum-boiling azeotrope? A Each substance increases the specific heat of the other B Each substance decreases the specific heat of the other C Each substance increases the vapor pressure of the other D Each substance decreases the vapor pressure of the other A B C D 10 Which of the following combinations would be likely to form a minimum-boiling azeotrope? A B C D 0.04 or 0.70 0.20 or 0.40 0.30 or 0.96 0.60 or 0.80 An ethanol and water solution can be distilled to, at best, a 95% ethanol solution, which boils at 78°C What can be said about this mixture? A It is a minimum-boiling azeotrope with water as the most volatile component B It is a minimum-boiling azeotrope with ethanol as the most volatile component C It is a maximum-boiling azeotrope with water as the most volatile component D It is a maximum-boiling azeotrope with ethanol as the most volatile component Water and chlorobenzene Water and nitric acid Water and hydrogen peroxide Water and acetone Which of the following shows the boiling point of an aqueous sodium chloride solution as a function of the percent sodium chloride in the solution by weight? Based on Figure 1, if a mixture of Solution A and Solution B boils at 40°C, what is the mole fraction of B in the vapor? 11 Which of the following describes the effect on boiling point when a nonvolatile solute is added to a liquid? A B C D ∆Tb = KbM ∆Tb = Kb / M ∆Tb = Kbm ∆Tb = Kb / m GO ON TO THE NEXT PAGE KAPLAN MCAT Passage III (Questions 12–17) Robert Millikan is credited with showing experimentally that the electron has a definite, finite charge His experiment, in a somewhat simplified form, is described below The setup is shown in Figure 12 What is the electric field between the plates in Figure if the voltage VAB is 20 volts? A 0.02 V/m B 0.2 V/m C 20 V/m D x 103 V/m 13 What is the direction of an electric field between the plates that holds a negatively charged droplet motionless? A B C D Two horizontal parallel plates, A and B are placed cm apart, and are insulated from one another A potential difference VAB is applied across the plates, producing an electric field between them Drops of oil between 10–6 and 10–5 cm in diameter are sprayed through a hole in the top plate into the electric field The drops accumulate electric charge, and are therefore affected by the electric field In the case of a negatively-charged drop, the potential difference across the plates is adjusted until the drop is motionless, the gravitational force being exactly balanced by the upward electrostatic force The mass of the droplet and the potential difference across the plates is measured, and from this the electric charge on the drop can be determined This procedure is then repeated with another drop Millikan found, when he calculated the electric charge required from the balanced forces, that the measured charges were integer multiples of a specific electric charge This “unit” charge was assumed to be the charge of a single electron (Note: acceleration due to gravity = 9.8 m/s2; density of oil = 800 kg/m3.) Upwards Downwards To the left To the right 14 If the separation of the plates is reduced, but the potential difference across them remains constant, which of the following statements must be true? I The electric field increases II The magnetic field increases III The capacitance increases A B C D I only I and II only I and III only II ant III only 15 An oil drop is stationary within an electric field of E that is set up between two parallel plates If the oil drop has a volume of V and a density of ρ, how many excess electrons does it carry? (Note: The fundamental unit of charge is e.) A B C D E/ρgV eE/ρgV ρgV/E ρgV/eE GO ON TO THE NEXT PAGE as developed by Physical Sciences 16 A negatively charged droplet has a mass of x 10–16 kg and carries a charge of x 10–18 C The droplet falls through the hole in the upper plate when the electric field is V/m How does the drop move within the plates as the electric field is increased slowly from V/m to 800 V/m? (Note: Assume that the drop remains between the plates at all times.) A It moves downwards, stops, then moves upwards B It moves downwards, accelerating all the time C It moves downwards, stops, then moves downwards again D It moves downwards, stops, and remains stationary 17 A drop of oil of mass x 10–16 kg is at rest on the bottom of a plate of a parallel plate combination when the electric field is zero An electric field of x 103 V/m is then applied between the plates, accelerating the drop towards the top plate What will be the resultant acceleration of the drop if it carries a negative charge of x 10-18 C? A 9.8 m/s2 B 14.2 m/s2 C 24.0 m/s2 D 28.4 m/s2 Questions 18 through 22 are NOT based on a descriptive passage 18 What is the calcium concentration of a solution formed by adding mol of CaCl2 to L of distilled water at 298K? A B C D 1M 1m 2M 2m 19 Two blocks of the same density are completely submerged in water One block has a mass equal to m and volume equal to V The other has a mass equal to 2m What is the ratio of the first block’s apparent weight to the second block’s apparent weight? A B C D 1:1 1:2 2:1 4:1 20 In which atomic orbital(s) to the alkaline earth elements contain valence electrons? A B C D s d s and d s, d, and p 21 In the arrangement shown below, a current flows from P to Q Which of the following could represent the current flowing through R1, R2, R3, and R4, respectively? R 1= R R 3= 2R P Q R 2= R A B C D R 4= R 1.0 A, 2.0 A, 1.0 A, 2.0 A 1.0 A, 1.0 A, 0.5 A, 1.0 A 3.0 A, 3.0 A, 4.0 A, 2.0 A 3.0 A, 3.0 A, 2.0 A, 4.0 A GO ON TO THE NEXT PAGE KAPLAN MCAT 22 What is the ratio of the maximum possible number of electrons in an f subshell to the maximum number of electrons in a p subshell? A 2:1 B 4:1 C 7:3 D 15:6 Passage IV (Questions 23–27) A chemistry teacher wishes to set up a demonstration of a redox reaction for her class Students are provided with the materials necessary to set up the apparatus shown below Experiment 1: Students were provided with M hydrochloric acid and offered a choice of various metals The metals offered to the students, along with their reduction potentials, are listed below Metal E°(V) Silver Copper Tin Nickel Iron 0.80 0.34 –0.14 –0.25 –0.44 Each student group tested a different metal for reactivity by placing it in a beaker and observing the gas produced (if any) from the reaction Each metal’s reaction was timed and the rate at which gas was produced was recorded Experiment 2: Students were given the supplies necessary to set up a galvanic cell for the purpose of determining the reduction potential of zinc, also using hydrochloric acid The reduction potential was determined to be –0.76V Both experiments were carried out at 25°C and atm GO ON TO THE NEXT PAGE as developed by Physical Sciences 23 When hydrochloric acid is added to each of the metals listed in Table 1, which metals will produce a reaction? A B C D Ag, Cu Sn, Ni, Fe All of the metals None of the metals 24 Of the metals listed, which will produce the most vigorous reaction? A B C D Silver Copper Tin Iron 25 In Experiment 2, which of the following galvanic cell setups would be most useful for determining the reduction potential of zinc? A Zinc electrode as anode in a M Zn2+ solution; hydrogen electrode as cathode in a M H+ solution B Zinc electrode as cathode in a M Zn2+ solution; hydrogen electrode as anode in a M H+ solution C Zinc electrode as anode in a M Zn2+ solution; copper electrode as cathode in a M Cu 2+ solution D Zinc electrode as cathode in a M Zn2+ solution; copper electrode as anode in a M Cu 2+ solution 26 What is the role of HCl in Experiment 2? A B C D It is a reducing agent It is an oxidizing agent It is a catalyst It in a solvent 27 If Experiment were carried out using zinc, what would be the maximum weight of the sample that could be used to ensure that all the gas produced could be collected in a L bottle? A B C D 1.3 g 1.4 g 2.6 g 2.9 g KAPLAN END OF TEST MCAT ANSWER KEY: A 11 B 12 B 13 C 14 D 15 10 10 D A B B B 16 17 18 19 20 C D B C D 21 22 23 24 25 A B B B A 26 B 27 C D C B D A ...Physical Sciences Test Time: 35 Minutes Number of Questions: 27 MCAT PHYSICAL SCIENCES DIRECTIONS: Most of the questions in the following Physical Sciences test are organized into groups,... relationship of the speed of light in each of these media? A fastest in air, slower in aqueous humor, slowest in vitreous humor B fastest in vitreous humor, slower in aqueous humor, slowest in air... below Metal E°(V) Silver Copper Tin Nickel Iron 0.80 0.34 –0.14 –0.25 –0.44 Each student group tested a different metal for reactivity by placing it in a beaker and observing the gas produced