{"id":23141,"date":"2022-01-05T19:35:02","date_gmt":"2022-01-05T19:35:02","guid":{"rendered":"https:\/\/assignmenttutors.net\/blog\/purifying-acetanilide-by-recrystallization-chemistry-homework-help\/"},"modified":"2022-01-05T19:35:02","modified_gmt":"2022-01-05T19:35:02","slug":"purifying-acetanilide-by-recrystallization-chemistry-homework-help","status":"publish","type":"post","link":"https:\/\/assignmenttutors.net\/blog\/purifying-acetanilide-by-recrystallization-chemistry-homework-help\/","title":{"rendered":"Purifying acetanilide by recrystallization | Chemistry homework help"},"content":{"rendered":"<div>\n<p><strong>\u00a0<\/strong><\/p>\n<p><strong><span>Purifying Acetanilide by<\/span><\/strong><\/p>\n<p><strong><span>Recrystallization<\/span><\/strong><\/p>\n<p>\u00a0<\/p>\n<p>1. The solubility of benzoic acid in water is 6.80 g per 100 mL at 100\u00b0C and 0.34 g per 100 mL at 25\u00b0C.<\/p>\n<p>Show your calculations for the questions below.<\/p>\n<p>(a) Calculate the minimum volume of water needed to dissolve 1.00 g of benzoic acid at 100\u00b0C.<\/p>\n<p>(b) Calculate the maximum theoretical percent recovery from the recrystallization of 1.00 g of benzoic<\/p>\n<p>acid from 15 mL of water, assuming the solution is filtered at 25\u00b0C.<\/p>\n<p>2. The solubility of acetanilide in your recrystallizing solvent is 5.0 mg per mL at 10\u00b0C. (10\u00baC is the<\/p>\n<p>approximate temperature of an ice\/water bath). Show your calculations for the questions below.<\/p>\n<p>(a) Calculate the theoretical maximum percent recovery in this experiment, assuming a 15.0-mL<\/p>\n<p>recrystallizing solution is filtered at 10\u00b0C.<\/p>\n<p>(b) Calculate the percent recovery of the acetanilide produced in your experiment.<\/p>\n<p>(c) How do your results compare to the theoretical maximum percent recovery? <strong><span>Explain any difference<\/span><\/strong><\/p>\n<p>you may have observed. Why is the theoretical maximum percent recovery (calculated in 2a above) not<\/p>\n<p>necessarily applicable your experiment? <em><span>Aside from technical or human error <\/span><\/em>(such as spillage,<\/p>\n<p>incomplete transfers, loss on the filter paper, loss due to excessive washing, etc.) or slight differences involume of solvent or temperature of the ice bath, <strong><span>what assumptions or estimations were made in this<\/span><\/strong><\/p>\n<p><strong><span>calculation <\/span><\/strong>which may not apply to your results?<\/p>\n<p>3. A student rushed through this experiment. Describe the effect that the following procedural changes<\/p>\n<p>would have on the percent recovery of acetanilide; would the % recovery by <em><span>higher<\/span><\/em>, or <em><span>lower<\/span><\/em>? Briefly<\/p>\n<p>explain the basis of each answer.<\/p>\n<p>(a) Rather than adding 0.5-mL portions of boiling solvent to the acetanilide, the student added 5-mL<\/p>\n<p>portions of boiling solvent.<\/p>\n<p>(b) The student forgot to cool 5 mL of solvent in Part 4 and washed the crystals with room-temperature<\/p>\n<p>solvent.<\/p>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n<p><strong><span>Separating Acids and Neutral Compounds by<\/span><\/strong><\/p>\n<p><strong><span>Solvent Extraction<\/span><\/strong><\/p>\n<p>1. Based on the amounts of p-toluic acid and acetanilide you recovered, estimate the<\/p>\n<p>composition of the original mixture, assuming that you lost equal amounts of each<\/p>\n<p>compound. Show your calculations. <em><span>Express the composition as percentages of each<\/span><\/em><\/p>\n<p><em><span>component: For example \u201cthe original mixture was 30% p-toluic acid and 70%<\/span><\/em><\/p>\n<p><em><span>acetanilide\u201d<\/span><\/em>.<\/p>\n<p>2. What product would you obtain if you evaporated the water from the NaOH layer prior to<\/p>\n<p>acidifying the layer?<\/p>\n<p>3. Suppose that you used dichloromethane instead of diethyl ether as the nonpolar solvent in<\/p>\n<p>this experiment. What changes in the procedure would you make in view of the fact that<\/p>\n<p>dichloromethane is more dense than water?<\/p>\n<p>\u00a0<\/p>\n<p>4. Benzoic acid (C<span>6<\/span>H<span>5<\/span>\u2014COOH) is a weak acid and naphthalene is neutral, neither acidic or<\/p>\n<p>basic. Prepare a flowchart for the separation and recovery of benzoic acid and<\/p>\n<p>naphthalene.<\/p>\n<p>Benzoic Acid Naphthalene<\/p>\n<p>solubility in water: <em><span>poor <\/span><\/em>solubility in water: <em><span>poor<\/span><\/em><\/p>\n<p>solubility in ether: <em><span>good <\/span><\/em>solubility in ether: <em><span>good<\/span><\/em><\/p>\n<p>5. After comparing the melting points of each of your compounds to their respective<\/p>\n<p>literature values, comment on the purity of each compound. (You may skip this question if your<\/p>\n<p>instructor did not have you acquire melting points).<\/p>\n<p><span>O OH<\/span><\/p>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n<p>1. Briefly describe the hazards you should be aware of when you work with:<\/p>\n<p>(a) diethyl ether<\/p>\n<p>(b) 3M HCl<\/p>\n<p>2. Briefly explain or describe the following:<\/p>\n<p>(a) How would you determine which layer is the aqueous layer after you add NaOH solution to<\/p>\n<p>the ether solution of your compounds?<\/p>\n<p>(c) What visible evidence(s) of reaction will you see when you acidify the NaOH extract with<\/p>\n<p>HCl solution?<\/p>\n<p>(d) In which layer would <em><span>p<\/span><\/em>-toluic acid be more soluble if <em><span>p<\/span><\/em>-toluic acid were added to a two-layer<\/p>\n<p>mixture of diethyl ether and water?<\/p>\n<p><span>13<\/span><\/p>\n<p>Solvent Extraction, Pre-lab page 2<\/p>\n<p>(e) How would the results differ if you added sodium <em><span>p<\/span><\/em>-toluate instead of <em><span>p<\/span><\/em>-toluic acid to the<\/p>\n<p>two-layer mixture of diethyl ether and water?<\/p>\n<p>4. How many milliliters of 3.0 M HCl would be required to neutralize 30. mL of 0.50 M<\/p>\n<p>NaOH? (<strong><span>Show your work<\/span><\/strong>). (hint: this is a general chemistry question! Remember that the<\/p>\n<p>acid HCl and the base NaOH react in a 1:1 molar ratio. The number of moles of acid need to<\/p>\n<p>equal the number of moles of base to effect complete neutralization).<\/p>\n<p>5. Briefly explain how you will isolate <em><span>p<\/span><\/em>-toluic acid after it is extracted it into NaOH solution.<\/p>\n<p>6. Write the equation for the chemical reaction of the toluate ion that will occur when you<\/p>\n<p>add HCl solution to the NaOH extract in part 3.<\/p>\n<p>\u00a0<\/p>\n<p><span>SN1 Reaction: A Kinetic study<\/span><\/p>\n<p>\u00a0<\/p>\n<p>\u00a0<\/p>\n<p><strong><span>Post-Laboratory Questions <\/span><\/strong>(attach your responses on a separate sheet)<\/p>\n<p>1. From the experimental data, prepare a table of the following values. Record all calculated<\/p>\n<p>results to the proper number of significant figures. Note that V and V<span>\u00a5 <\/span>are the <strong><em><span>total <\/span><\/em><\/strong>volumes of<\/p>\n<p>NaOH solution delivered; they are not burette readings (unless, of course, your initial buret<\/p>\n<p>reading was 0.00 mL). Base your calculations on the actual value of V<span>\u00a5 <\/span>that you measured in lab<\/p>\n<p>&#8211; <strong><span>not the theoretical value<\/span><\/strong>! Time, t, is the elapsed time in seconds (its OK to use minutes if you<\/p>\n<p>prefer). Use Equation 10 to calculate the values of <em><span>k<\/span><\/em>.<\/p>\n<p><strong><em><span>t (sec) V (mL) V\/V<\/span><\/em><\/strong><span>\u00a5 <\/span><strong><em><span>(1 &#8211; V\/V<\/span><\/em><\/strong><span>\u00a5<\/span><strong><em><span>) ln(1 &#8211; V\/V<\/span><\/em><\/strong><span>\u00a5<\/span><strong><em><span>) <\/span><\/em><\/strong><strong><em><span>k<\/span><\/em><\/strong><\/p>\n<p>2. Prepare a graph of ln(1 \u2013 V\/V<span>\u00a5<\/span><em><span>) <\/span><\/em>versus time, t. Using a computer program or a graphing<\/p>\n<p>calculator, determine the best straight line through your data points. (See the supplement to this<\/p>\n<p>lab for detailed instructions on how to determine best fit if you are unfamiliar with this process).<\/p>\n<p><strong><span>This graph should be properly labeled and drawn to scale<\/span><\/strong>. Do the data support the S<span>N<\/span>1<\/p>\n<p>mechanism? Briefly explain.<\/p>\n<p>3. Calculate the value of k from the slope of the line from the graph in 2.<\/p>\n<p>4. Using the values of k which you determined above (in question #1), calculate the average<\/p>\n<p>value of <em><span>k, <\/span><\/em>and estimate its uncertainty. One way to estimate its uncertainty is to<\/p>\n<p>(1) calculate an average value of <em><span>k<\/span><\/em><\/p>\n<p>(2) calculate the absolute value of the deviation of each value from the average value<\/p>\n<p>(3) calculate the average of these deviations.<\/p>\n<p>Prepare a table which shows the deviation for each datum, and report the average value of <em><span>k <\/span><\/em>and<\/p>\n<p>the average deviation. It may be convenient for you to include these data in the table you prepare<\/p>\n<p>for post-lab question #1, above.<\/p>\n<p>Note: What you are doing here is a standard statistical way of measuring <em><span>reproducibility<\/span><\/em>.<\/p>\n<p>Theoretically, the value of k should be the same for all trials. In practice, however, you almost<\/p>\n<p>certainly will observe some variation in the calculated values of k. The average deviation is a<\/p>\n<p>way of expressing in a single number how much variability you have in your data. Low average<\/p>\n<p>deviations mean your numbers are all close together; high average deviation means you have a<\/p>\n<p>lot of \u201cnoise\u201d or \u201cscatter\u201d in your data.<\/p>\n<p><span>12<\/span><\/p>\n<p><strong><span>Pre-Laboratory Assignment <\/span><\/strong>S<span>N<\/span>1 Reaction: A Kinetic Study<\/p>\n<p>Name ________________________________________________________________<\/p>\n<p><em><span>Note: you may wish to copy this pre-lab before you submit it. (The results of pre-lab question<\/span><\/em><\/p>\n<p><em><span>#2 will be helpful for your lab calculations)<\/span><\/em>.<\/p>\n<p>1. Describe briefly the hazards associated with the reaction mixture and the safety precautions<\/p>\n<p>you must take when performing the experiment.<\/p>\n<p>2. Assume that you use 1.00 mL of 2-chloro-2-methylpropane. Calculate the following<\/p>\n<p>quantities. <strong><span>Be sure to show your calculations; you will NOT receive credit if work is not<\/span><\/strong><\/p>\n<p><strong><span>shown!<\/span><\/strong><\/p>\n<p>a. the number of moles of 2-chloro-2-methylpropane used. The density of the liquid is<\/p>\n<p>0.851 g\/mL.<\/p>\n<p><span>b. the number of moles of HCl produced by complete solvolysis of 1.00 mL of 2-chloro-2-<\/span><\/p>\n<p><span>methylpropane.<\/span><\/p>\n<p><span>13<\/span><\/p>\n<p><span>S<\/span><span>N<\/span><span>1 Reaction: A Kinetic Study, Pre-lab page 2<\/span><\/p>\n<p><span>c. the volume in milliliters of 0.350 M NaOH required to neutralize the HCl produced by<\/span><\/p>\n<p><span>complete solvolysis of 1.00 mL of 2-chloro-2-methylpropane. (This is referred to as V<\/span><span>\u00a5 <\/span><span>in your<\/span><\/p>\n<p><span>lab manual).<\/span><\/p>\n<p><span>d. the volume in milliliters of 0.350M NaOH required to neutralize the HCI produced when<\/span><\/p>\n<p><span>solvolysis of 1.00 mL of 2-chloro-2-methylpropane is 50% complete. (This is referred to<\/span><\/p>\n<p><span>as V<\/span><span>50% <\/span><span>in your lab manual; the volume of base consumed when the reaction is 50%<\/span><\/p>\n<p><span>complete).<\/span><\/p>\n<p><span>Note: you may wish to record the values of V<\/span><span>\u00a5 <\/span><span>and V<\/span><span>50% <\/span><span>separately before you turn in your<\/span><\/p>\n<p><span>pre-laboratory assignment; you will need these values during the experiment.<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>Studying S<\/span><span>N<\/span><span>1 Reactions:<\/span><\/p>\n<p><span>Nucleophilic Substitution at<\/span><\/p>\n<p><span>Saturated Carbon<\/span><\/p>\n<p><strong><span>Post-Laboratory Questions<\/span><\/strong><\/p>\n<p><span>1. When you compared 2-bromo-2-methylpropane and 2-chloro-2-methylpropane (in part<\/span><\/p>\n<p><span>one), what were the relative rates of the two reactions?<\/span><\/p>\n<p><span>2. Based on your answer to question 1, which is the better leaving group, Br<\/span><span>&#8211; <\/span><span>or Cl<\/span><span>&#8211; <\/span><span>?<\/span><\/p>\n<p><span>HBr is a <\/span><strong><span>stronger <\/span><\/strong><span>acid than HCl. Are these results consistent with the relative<\/span><\/p>\n<p><span>basicities of these two ions? <\/span><strong><span>Explain <\/span><\/strong><span>your answer.<\/span><\/p>\n<p><span>3. Which compound, 2-bromo-2-methylpropane or 2-bromopropane, reacted faster in<\/span><\/p>\n<p><span>your <\/span><span>S<\/span><span>N<\/span><span>1 <\/span><span>experiment? How are the reactivities of 2-bromo-2-methylpropane and<\/span><\/p>\n<p><span>2-bromopropane related to the stabilities of the carbocations produced as intermediates in<\/span><\/p>\n<p><span>the reaction? <\/span><strong><span>Explain <\/span><\/strong><span>your answer.<\/span><\/p>\n<p><span>4. Which of the two solvent mixtures, 40% 2-propanol or 60% 2-propanol, is more<\/span><\/p>\n<p><span>polar? <\/span><strong><span>Explain <\/span><\/strong><span>your answer.<\/span><\/p>\n<p><span>5. In which of the two solvent mixtures did 2-bromo-2-methylpropane react faster?<\/span><\/p>\n<p><span>Account for your results in terms of the effect of solvent polarity on the rate-determining<\/span><\/p>\n<p><span>step in this <\/span><span>S<\/span><span>N<\/span><span>1 <\/span><span>reaction.<\/span><\/p>\n<p><span>6. Use your results to explain which variable \u2014 leaving group, alkyl structure, or solvent<\/span><\/p>\n<p><span>polarity \u2014 has the greatest impact on the rate of an <\/span><span>S<\/span><span>N<\/span><span>1 <\/span><span>reaction. In other words, which<\/span><\/p>\n<p><span>variable had the most pronounced effect on the observed times?<\/span><\/p>\n<p><span>9<\/span><\/p>\n<p><strong><span>Pre-Laboratory Assignment Studying S<\/span><\/strong><strong><span>N<\/span><\/strong><strong><span>1 reactions<\/span><\/strong><\/p>\n<p><span>Name _________________________________________________________________<\/span><\/p>\n<p><span>1. Why do tertiary alkyl halides typically undergo <\/span><span>S<\/span><span>N<\/span><span>1 <\/span><span>substitution reactions more rapidly<\/span><\/p>\n<p><span>than do primary or secondary alkyl halides?<\/span><\/p>\n<p><span>2. Show a complete and balanced reaction for the solvolysis of<\/span><\/p>\n<p><span>2-bromo-2-methylpropane in water. Also show a complete and balanced reaction for the<\/span><\/p>\n<p><span>solvolysis of 2-bromopropane in water. (It is NOT necessary to show intermediates or<\/span><\/p>\n<p><span>mechanisms, just the overall reactions). Which of these reactions is kinetically favored?<\/span><\/p>\n<p><span>3. How does the <\/span><span>S<\/span><span>N<\/span><span>1 <\/span><span>reaction in this experiment cause the acid\/base indicator,<\/span><\/p>\n<p><span>phenolphthalein, to change color? Briefly explain.<\/span><\/p>\n<p><span>10<\/span><\/p>\n<p><span>4. Why is it important that the volume of 0.5 M NaOH be measured exactly? What<\/span><\/p>\n<p><span>would happen if you put different amounts of NaOH in the different reaction vessels,<\/span><\/p>\n<p><span>what error would this cause in your results?<\/span><\/p>\n<p><span>5. Which is the better leaving group, Cl<\/span><span>-1 <\/span><span>or Br<\/span><span>-1 <\/span><span>? Briefly explain why one is better than<\/span><\/p>\n<p><span>the other.<\/span><\/p>\n<p><span>Extract caffeine from i tea<\/span><\/p>\n<p><strong><span>Post Laboratory Questions <\/span><\/strong><span>(attach your responses on a separate sheet)<\/span><\/p>\n<p><span>1. Calculate the mass percent of caffeine in your instant tea sample.<\/span><\/p>\n<p><span>2. On the average, people use one teaspoon (2.5 g) of instant tea to make an 8.0-oz glass of iced tea. The<\/span><\/p>\n<p><span>average glass of iced tea contains 10. mg of caffeine per oz.<\/span><\/p>\n<p><span>(a) Based on this information, calculate the mass percent of caffeine in a glass of iced tea.<\/span><\/p>\n<p><span>(b) Are your experimental results consistent with these facts? Briefly explain.<\/span><\/p>\n<p><span>(c) If not, explain why your experimental results may differ from these data.<\/span><\/p>\n<p><span>7<\/span><\/p>\n<p><strong><span>Pre-Laboratory Assignment Isolating Caffeine from Tea<\/span><\/strong><\/p>\n<p><span>Name _________________________________________________________<\/span><\/p>\n<p><span>1. Why should you use a fume hood when working with dichloromethane?<\/span><\/p>\n<p><span>2. Why is gentle shaking necessary during the extraction of caffeine from tea?<\/span><\/p>\n<p><span>3. Why is it important to not overheat the dichloromethane while extracting the caffeine?<\/span><\/p>\n<p><span>4. During <\/span><em><span>recrystallization<\/span><\/em><span>, why should the 2-propanol be kept hot while dissolving the crude crystals?<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>Synthesize acetylsalicylic acid (aspirin)<\/span><\/p>\n<p><strong><span>Post-Laboratory Questions <\/span><\/strong><span>(attach your responses on a separate sheet)<\/span><\/p>\n<p><span>1. Calculate the % yield of aspirin in your experiment. Be sure to fully show your calculations<\/span><\/p>\n<p><span>for theoretical yield and % yield; you will NOT receive credit if work is not shown!<\/span><\/p>\n<p><span>2. a. Other than human error, impurities in the starting materials, or equipment<\/span><\/p>\n<p><span>malfunctions, can you think of any reason why the aspirin might not be completely pure?<\/span><\/p>\n<p><span>What steps could be taken to improve the purity of your product?<\/span><\/p>\n<p><span>b. If you determined the melting point of the aspirin sample, comment on the purity of<\/span><\/p>\n<p><span>your product.<\/span><\/p>\n<p><span>3. Using your textbook or another appropriate reference, show a <\/span><strong><em><span>detailed mechanism <\/span><\/em><\/strong><span>for the<\/span><\/p>\n<p><span>esterification reaction in this experiment.<\/span><\/p>\n<p><strong><span>\u00a0<\/span><\/strong><\/p>\n<p><strong><span>\u00a0<\/span><\/strong><\/p>\n<p><strong><span>Pre-Laboratory Questions <\/span><\/strong><span>Synthesis of Aspirin<\/span><\/p>\n<p><span>Name _________________________________________________________________<\/span><\/p>\n<p><span>1. Calculate the theoretical yield of aspirin, in grams, for this experiment, assuming<\/span><\/p>\n<p><span>that you start with 2.0 grams of salicylic acid and 5.0 mL of acetic anhydride. The<\/span><\/p>\n<p><span>density of acetic anhydride is 1.08 g\/mL. You must show ALL of your calculations to<\/span><\/p>\n<p><span>receive credit on this question and question #2. (<\/span><em><span>You may want to make a copy of this<\/span><\/em><\/p>\n<p><em><span>calculation and result before turning in the pre-lab; you will need this value for the<\/span><\/em><\/p>\n<p><em><span>post-lab questions, also<\/span><\/em><span>).<\/span><\/p>\n<p><span>2. If 1.9 grams of aspirin were obtained in this experiment, what would be the percent<\/span><\/p>\n<p><span>yield?<\/span><\/p>\n<p><span>3. Write the equation for the reaction which occurs when acetic anhydride is mixed with<\/span><\/p>\n<p><span>water. (please show <\/span><em><span>structures <\/span><\/em><span>or <\/span><em><span>structural formulae <\/span><\/em><span>in your response).<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>Oxidation of an Alcohol:<\/span><\/p>\n<p><span>Oxidizing Methoxybenzyl Alcohol to<\/span><\/p>\n<p><span>Methoxybenzaldehyde Using<\/span><\/p>\n<p><span>Phase-Transfer Catalysis<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><strong><span>Post-Laboratory Questions <\/span><\/strong><span>(attach your responses on a separate page)<\/span><\/p>\n<p><span>1. Calculate the percent yield of your product. [Note: if the amount of methoxybenzyl alcohol<\/span><\/p>\n<p><span>you used differs from the amount listed in the \u201cReagents and Properties\u201d section of the lab, you<\/span><\/p>\n<p><span>will have to re-calculate the theoretical yield, based on the amount of alcohol actually used].<\/span><\/p>\n<p><em><span>Make certain to show your work for this calculation<\/span><\/em><span>.<\/span><\/p>\n<p><span>2. Calculate R<\/span><span>f <\/span><span>values for methoxybenzyl alcohol and methoxybenzaldehyde, using the 20-min<\/span><\/p>\n<p><span>spotting time. Why does the alcohol have a lower R<\/span><span>f <\/span><span>value than the aldehyde?<\/span><\/p>\n<p><span>Note: you should submit the TLC plates! They belong in the results section. Tape them onto a<\/span><\/p>\n<p><span>sheet of paper and label them appropriately. If you worked with a partner, make a note if your<\/span><\/p>\n<p><span>TLC plates are with your partner\u2019s report.<\/span><\/p>\n<p><span>3. The ethyl acetate layer was extracted with NaOH to remove any traces of methoxybenzoic<\/span><\/p>\n<p><span>acid that may have been produced by over-oxidation of the alcohol.<\/span><\/p>\n<p><span>a. Draw the structure for methoxybenzoic acid.<\/span><\/p>\n<p><span>b. Show the balanced reaction of NaOH and methoxybenzoic acid.<\/span><\/p>\n<p><span>c. If you wished to isolate and collect methoxybenzoic acid from the NaOH solution,<\/span><\/p>\n<p><span>explain how this could be done. (hint: methoxybenzoic acid is not soluble in water).<\/span><\/p>\n<p><span>4. Explain how TLC could be used to monitor the reduction of methoxybenzoic acid to<\/span><\/p>\n<p><span>methoxybenzaldehyde acid using LiAlH<\/span><span>4 <\/span><span>as a reducing agent.<\/span><\/p>\n<p><span>5. In this experiment, students often note that on the TLC plates, the spot for the standard<\/span><\/p>\n<p><span>p-methoxybenzaldehyde has a very faint second spot with a very low R<\/span><span>f<\/span><span>. You may have noticed<\/span><\/p>\n<p><span>this on your own TLC plates &#8211; it is due to a contaminant in the benzaldehyde. The R<\/span><span>f <\/span><span>of this spot<\/span><\/p>\n<p><span>is lower than that of p-methoxybenzyl alcohol; what do you think this spot may be? (Hint: the<\/span><\/p>\n<p><span>contaminant appears after p-methoxybenzaldehyde has been stored for a long period of time <\/span><em><span>in<\/span><\/em><\/p>\n<p><em><span>an oxygen atmosphere <\/span><\/em><span>such as air; the contaminant is NOT observed if the<\/span><\/p>\n<p><span>p-methoxybenzaldehyde is stored away from oxygen).<\/span><\/p>\n<p><span>11<\/span><\/p>\n<p><strong><span>Pre-Laboratory Assignment Oxidizing Methoxybenzyl Alcohol<\/span><\/strong><\/p>\n<p><span>Name ___________________________________________________________________<\/span><\/p>\n<p><span>1. What safety precautions must be observed when using<\/span><\/p>\n<p><span>(a) ethyl acetate?<\/span><\/p>\n<p><span>(b) dichloromethane?<\/span><\/p>\n<p><span>2. Using the data in the <\/span><em><span>Reagents and Properties <\/span><\/em><span>table, calculate the theoretical yield of<\/span><\/p>\n<p><span>methoxybenzaldehyde, assuming you start with 1.50 g of the alcohol. (Assume the alcohol is the<\/span><\/p>\n<p><span>limiting reactant). <\/span><strong><span>Be sure to show your work; you will NOT receive credit if work is not<\/span><\/strong><\/p>\n<p><strong><span>shown<\/span><\/strong><span>. You may wish to make a copy of this calculation to assist you with your post-lab<\/span><\/p>\n<p><span>questions.<\/span><\/p>\n<p><span>3. Explain why a phase-transfer catalyst is used when oxidizing methoxybenzyl alcohol using<\/span><\/p>\n<p><span>NaOCl.<\/span><\/p>\n<p><span>12<\/span><\/p>\n<p><strong><span>Pre-Laboratory Assignment Oxidizing Methoxybenzyl Alcohol<\/span><\/strong><\/p>\n<p><span>Name ___________________________________________________________________<\/span><\/p>\n<p><span>4. Draw the structure of the expected organic product for each of the reactions shown below:<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p><span>\u00a0<\/span><\/p>\n<p>\u00a0<\/p>\n<p><span><img loading=\"lazy\" decoding=\"async\" src=\"\" alt=\"structures.png\" width=\"602\" height=\"451\"\/><\/span><\/p>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>\u00a0 Purifying Acetanilide by Recrystallization \u00a0 1. The solubility of benzoic acid in water is 6.80 g per 100 mL at 100\u00b0C and 0.34 g per 100 mL at 25\u00b0C. Show your calculations for the questions below. (a) Calculate the minimum volume of water needed to dissolve 1.00 g of benzoic acid at 100\u00b0C. (b) [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[16],"tags":[],"class_list":["post-23141","post","type-post","status-publish","format-standard","hentry","category-education"],"_links":{"self":[{"href":"https:\/\/assignmenttutors.net\/blog\/wp-json\/wp\/v2\/posts\/23141","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/assignmenttutors.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/assignmenttutors.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/assignmenttutors.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/assignmenttutors.net\/blog\/wp-json\/wp\/v2\/comments?post=23141"}],"version-history":[{"count":0,"href":"https:\/\/assignmenttutors.net\/blog\/wp-json\/wp\/v2\/posts\/23141\/revisions"}],"wp:attachment":[{"href":"https:\/\/assignmenttutors.net\/blog\/wp-json\/wp\/v2\/media?parent=23141"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/assignmenttutors.net\/blog\/wp-json\/wp\/v2\/categories?post=23141"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/assignmenttutors.net\/blog\/wp-json\/wp\/v2\/tags?post=23141"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}