C/P AAMC Fl #3 Question with complete solution 2023

C/P AAMC Fl #3 Question with complete solution 2023For a thermodynamic mixture of isomeric products the relative mole ratio of products is directly related to the relative stability of these products #2. What can be inferred from the results of scheme A about the relative thermodynamic stabilities of Compounds 4a and 4b Compound 4a is more stable than 4b The image shows that 4a is produced 60% and 4b 40%. --So 4a will be more stable among the two thermodynamic products #3. Which of the following compounds is most likely to be a major product in step 2 if the aldol condensation is NOT followed by a dehydration reaction? Ans in image --coz if there is no dehydration, then the OH would be present instead of the double bond --product of aldol condensation is b-hydroxyketone #4. Compound X is shown below.(image) If compound 2 is replaced with compound X, what will be the structure of the final product in steps 1 and 2? (Note: assume that the yields of steps 1 and 2 are not affected by substitution) Ans in image --coz this is the product of Michael addition followed by intramolecular aldol condensation (Robinson annulation) #5. What is the total amount of charge and energy, respectively, that the capacitor will store if it is connected to the battery on the railcar? 1.20C and 7.20J C=Q/V Energy stored by a capacitor = Ue = (1//2)CV^2 = (1/2)QV = (1/2)Q^2V Given V= 12V C = 100 x 10^-3 F Q = VC = (12)(100 x 10^-3) = 1.20 C Ue = (1/2)QV = (1/2)(1.20)(12) = 7.20J #6. Suppose that the railcar passes by a horn that is emitting a sound with a frequency f. Which of the following describes f' that the person on the railcar hears? f' > f before passing the horn, f' < f after passing it Due to doppler effect, the frequency that the person on the railcar hears before passing the horn is larger than the actual frequency of the sound emitted, while the person hears a frequency lower than the actual frequency after passing the horn --Before passing the horn, the object(rail car) is coming closer to the source (horn) so f'>f --After passing the horn, the object(railcar) is moving away from the source (horn) so f<f' Doppler effect The apparent frequency (f') of the source is increased as the source approaches the observer, and is decreased as the sources leaves the observer f' = ((V+_ Vo)/(V-+Vs))f #7. If no braking occurs, a total of how much power would be required to keep the railcar moving at 40m/s? Power = work done/ time Work done = Fd v= d/t --> d =vt W= Fd --> Fvt P = Fv = (1000N)(40) = 40000 W = 40 kW There are lot of force values given in the passage but we use 1000N coz the power required must match the work done by the friction force that tends to slow down the railcar Rest of the values of forces involve braking so can't use it since the question says that "If no braking occurs...." #8. If a generator-brake system alone were engaged when the railcar was moving, which of the following graphs would most accurately represent the subsequent speed of the railcar? Ans Image--> Coz the speed of the car decreases in time such that the decelerating force declines linearly with speed, according to the passage. Because the decelerating force is directly proportional to the deceleration acceleration, it follows that the decelerating acceleration itself declines linearly with speed. Finally, because the decelerating acceleration is the rate of change of velocity, or the slope of the velocity vs. time graph, then the slope of the graph must decrease in time F=ma, m will be constant, since force is decreasing linearly, acceleration is decreasing. Slope of v, t graph = a, so in the answer choices the slope cannot stay the same because a is changing not constant, and it is decreasing overall since deceleration First to be clear, the passage states "Force decreases linearly with Speed" BUT the axes on the graphs are Velocity vs Time. Choice A would be if you had a CONSTANT decelerating force Choice D shows the expected result of a LINEARLY DECREASING decelerating force. It helps to think of it conceptually. At high speed the force of deceleration will also be high, so the velocity will drop quickly (steep slope). At low speed the force of deceleration will be small, so the rate at which velocity drops will be slow (shallow slope). #9. The relative thermodynamic stability of isomeric organic compounds can be inferred from which of the following types of experimental data? A. Boiling points B. UV-visible absorption spectra C. Mass spectroscopic fragmentation patterns D. Heats of combustion D. Heats of combustion The relative thermodynamic stability of isomers can be determined based on the amount of heat produced when the compounds are combusted; less heat, greater stability