MCAT AAMC FL 1 CHem and Physics Questions and Answers 2023

MCAT AAMC FL 1 CHem and Physics Questions and Answers 2023 In the chromatography of the reaction mixture, water absorbed on cellulose functioned as the stationary phase. What was the principal factor determining the migration of individual components in the sample? A.Hydrogen bonding B.Solute concentration C.Stationary phase concentration D.Thickness of paper The correct answer is A. This is an Organic Chemistry question that falls under the content category "Separation and purification methods." The answer to this question is A because the relative amount of hydrogen bonding to the stationary phase will determine the relative rate of migration of the various components in the sample. It is a Scientific Reasoning and Problem Solving question because you are asked to evaluate an argument about causes and consequences (the primary reason for chemical separation during a chromatographic separation on cellulose). What assumption is being made if scientists conclude that aspartic acid was formed by the prebiological synthesis in the passage? A.Aspartic acid is unstable at temperatures below 150°C. B.All of the malic acid underwent the dehydration reaction to form fumaric/maleic acid. C.Compound A and cyanide were available on primitive Earth. D.The reaction between ammonia and fumaric acid was catalyzed by the presence of water. The correct answer is C. This is an Organic Chemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is C since, in order for the experimental reaction sequence to be relevant to the primordial formation of aspartic acid, the starting materials used (Compound A and cyanide) are assumed to have been available. It is a Reasoning About the Design and Execution of Research question because you are asked to reason about the appropriateness of particular research designs to evaluate a natural sciences question According to the developed chromatography plate shown below, what is the approximate Rf value of aspartic acid? A.0.20 B.0.50 C.5 D.10 This is an Organic Chemistry question that falls under the content category "Separation and purification methods." The answer to this question is A (0.20) because Rf is the ratio of the distance travelled by the analyte relative to the solvent front during a chromatographic separation. Aspartic acid travelled two units, while the solvent front travelled ten units, giving an Rf of 2/10 = 0.20 for aspartic acid. It is a Data-based and Statistical Reasoning question because you are asked to analyze and interpret data presented in a figure to draw a conclusion. Which of the following statements does NOT correctly describe the dehydration of malic acid to fumaric acid and maleic acid? A.The reaction occurs most readily with tertiary alcohols. B.The reaction involves the loss of a water molecule. C.The reaction has a carbocation intermediate. D.The reaction is stereospecific. The correct answer is D. This is an Organic Chemistry question that falls under the content category "Nature of molecules and intermolecular interactions." The answer to this question is D because the fact that both fumaric and maleic acid are produced means that the dehydration of malic acid is NOT stereospecific. It is a Data-based and Statistical Reasoning question because you are asked to analyze and interpret data (the outcome of a particular organic chemical reaction) in order to draw a conclusion. What type of functional group is formed when aspartic acid reacts with another amino acid to form a peptide bond? A.An amine group B.An aldehyde group C.An amide group D.A carboxyl group The correct answer is C. This is an Organic Chemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is C because the functional group that forms during peptide bond formation is known as an amide group. It is a Knowledge of Scientific Concepts and Principles question since you are asked to recognize the structural relationship between free amino acids and peptides. If 2-pentanol replaces 1-pentanol in the reaction shown in Figure 3, the rate of substitution is less because: A.the C-O bond in 2-pentanol is stronger than the C-O bond in 1-pentanol. B.there is a competing elimination reaction that slows the rate of substitution. C.there is more steric hindrance at the oxygen atom in 2-pentanol than in 1-pentanol, making protonation less likely. D.there is more steric hindrance at the 2-position of 2-pentanol than at the 1-position of 1-pentanol. The correct answer is D. This is an Organic Chemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is D because the rate of substitution of protonated alcohols is subject to steric hindrance. This inhibits the ability of nucleophiles to collide with the reacting electrophilic center and slows the rate of reaction. It is a Scientific Reasoning and Problem Solving question because you are asked to evaluate an argument about causes and consequences (the reason a reaction proceeds more slowly when a different reactant is used). If Experiment 2 is repeated with HCl and the compound shown below, which of the following compounds is NOT a direct product (without rearrangement)? Solution: The correct answer is A. This is an Organic Chemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is A because the structure shown in this response requires an additional shift of hydride atoms prior to elimination and is therefore NOT a direct product. It is a Scientific Reasoning and Problem Solving question because you are asked to bring together theory and observations to draw a conclusion. If a solution containing the compounds shown in Figure 4, is injected into a gas-liquid chromatograph, the first peak observed in the gc trace is attributable to which compound? Solution: The correct answer is B. This is an Organic Chemistry question that falls under the content category "Separation and purification methods." The answer to this question is B because 2-methyl-2-butene will exhibit the lowest molecular weight and also the weakest intermolecular forces of attraction. This substance will therefore migrate the fastest and be the first peak in the gas chromatograph (gc) trace. It is a Scientific Reasoning and Problem Solving question because you are asked to bring together theory and observations to draw a conclusion. What is the product of the reaction of Compound 1 (shown below) with HBr by the pathway shown in Figure 3? The correct answer is C. This is an Organic Chemistry question that falls under the content category "Nature of molecules and intermolecular interactions." The answer to this question is C because the incoming nucleophile displaces the leaving group form the opposite side of the reacting center during an SN2 reaction. It is a Scientific Reasoning and Problem Solving question because you are asked to bring together theory and observations to draw a conclusion. Acetic acid and ethanol react to form an ester product as shown below. In determining which reactant loses the -OH group, which of the following isotopic substitutions would be most useful? The correct answer is D. This is an Organic Chemistry question that falls under the content category "Structure, function, and reactivity of biologically-relevant molecules." The answer to this question is D because this experiment involves labeling a group which does not exchange with other groups present prior to reaction and will therefore give information about the true identity of the groups, which are exchanged during the reaction. It is a Reasoning about the Design and Execution of Research question because you are asked to reason about the appropriateness of particular research designs to evaluate a natural sciences question. whether or not that O18 is in the final compound will give us the information we want. If it is in the compound, we know that the ethanol kept its -OH group and therefore acetic acid lost its -OH. If the O18 isn't in the compound that means ethanol lost its -OH instead. A person, whose eye has a lens-to-retina distance of 2.0 cm, can only clearly see objects that are closer than 1.0 m away. What is the strength S of the person's eye lens? (Note: Use the thin lens formula 1/O+1/I=S.) A.-50 D B.-10 D C.51 D D.55 D This is a Physics question that falls under the content category "How light and sound interact with matter." The answer to this question is C because the strength of the eye lens is equal to the inverse of the focal length of the eye lens. Its numerical value is given by (1 m)-1+(0.02 m)-1=1 D+50 D=51 D. It is a Knowledge of Scientific Concepts and Principles question because you are asked to use mathematical equations to solve problems." Remember that the unit is m. Which statement correctly describes how enzymes affect chemical reactions? Stabilization of: A.the substrate changes the free energy of the reaction. B.the transition state changes the free energy of the reaction. C.the substrate changes the activation energy of the reaction. D.the transition state changes the activation energy of the reaction. Solution: The correct answer is D. This is a Biochemistry question that falls under the content category "Principles of chemical thermodynamics and kinetics." The answer is D because the stabilization of the transition state, not the substrate, provides binding energy that is used to lower the activation energy. It is a Knowledge of Scientific Concepts and Principles question because you are asked to recognize a fundamental principle of enzyme kinetics. Which of the following will decrease the percentage ionization of 1.0 M acetic acid, CH3CO2H(aq)? A.Chlorinating the CH3 group B.Diluting the solution C.Adding concentrated HCl(aq) D.Adding a drop of basic indicator The correct answer is C. This is a General Chemistry question that falls under the content category "Unique nature of water and its solutions." The answer to this question is C because HCl is a strong acid that will increase the amount of H+ in solution and thus decrease the percentage of CH3CO2H that ionizes. It is a Scientific Reasoning and Problem Solving question because you are asked to reason using a scientific principle (Le Châtelier's principle) to identify that adding a strong acid to a solution of weak acid will decrease the amount of ionization of the latter. When the current in the micro-robot's circuit increases and the resistance of the circuit remains constant, the voltage of the circuit: A.decreases. B.increases. C.is constant. D.is zero. The correct answer is B. This is a Physics question that falls under the content category "Electrochemistry and electrical circuits and their elements." The answer to this question is B because according to Ohm's law, current is equal to voltage divided by resistance. If current increases and resistance is constant, then voltage increases as well. It is a Scientific Reasoning and Problem Solving question because you are asked to determine and use scientific formulas to solve problems. Knowing that the speed of light in the vitreous humor is 2.1 × 108 m/s, what is the index of refraction of the vitreous humor? (Note: The speed of light in a vacuum is 3.0 × 108 m/s.) A.0.7 B.1.4 C.2.1 D.3.0 The correct answer is B. This is a Physics question that falls under the content category "How light and sound interact with matter." The answer to this question is B because the index of refraction of a medium is equal to the ratio of the speed of light in vacuum to the speed of light in the medium, thus it is equal to (3.0 ´ 108 m/s)/(2.1 ´ 108 m/s) = 1.4. It is a Scientific Reasoning and Problem Solving question because you are asked to determine and use scientific formulas to solve problems. index of refraction (n) n=c/v The intensity of the radiation emitted by the oxygen sensor is directly proportional to the: A.propagation speed of the radiation. B.wavelength of the radiation. C.polarization of photons emitted. D.number of photons emitted. The correct answer is D. This is a Physics question that falls under the content category "How light and sound interact with matter." The answer to this question is D because the energy of electromagnetic radiation is directly proportional to the number of photons, and the intensity of electromagnetic radiation is defined as energy emitted per unit time. Thus, intensity is directly proportional to the number of photons emitted. It is a Knowledge of Scientific Concepts and Principles question because you are asked to identify a relationship between closely related concepts. What is the energy of the photons emitted by the LED at a frequency of 610 THz? (Note: h = 6.6 × 10-34 J·s) This is a Physics question that falls under the content category "How light and sound interact with matter." The answer to this question is D because the energy of a photon of frequency 610 THz is equal to 6.6 ´ 10-34 J•s ´ 610 ´ 1012 Hz = 4 ´ 10-19 J. It is a Scientific Reasoning and Problem Solving question because you are asked to determine and use scientific formulas to solve problems. E=Hv THz 10^12 Hz PMPA = Pd + (Ps - Pd)/3 Pp = Ps - Pd What is the relationship between Pp, PMPA, and Pd? The correct answer is C. This is a Physics question that falls under the content category "Importance of fluids for the circulation of blood, gas movement, and gas exchange." The answer to this question is C because according to Equation 1, PPMA = Pd + (Ps - Pd)/3 = Pd +Pp/3; thus Pp = 3PMPA - 3Pd. It is a Knowledge of Scientific Concepts and Principles question because you are asked to use mathematical equations to solve problems. What percentage of standard atmospheric pressure is the pulse pressure of a healthy adult? A.10% B.6% C.2% D.1% This is a General Chemistry question that falls under the content category "Importance of fluids for the circulation of blood, gas movement, and gas exchange." The answer to this question is B because the pulse pressure in a healthy adult is (120 − 75) mmHg = 45 mmHg, and so the percentage is 45 mmHg/760 mmHg = 6%. It is a Knowledge of Scientific Concepts and Principles question because you are asked to use mathematical equations to solve problems.