1. Place 0.5 g of well-powdered 3-nitrobenzoic acid and a stirring bar into a 10 mL...
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
1. Place 0.5 g of well-powdered 3-nitrobenzoic acid and a stirring bar into a 10 mL round bottom flask. (The powdering is best done with a 25 mL Erlenmeyer and smooth surfaced weighing paper.) 2. Attach a drying tube containing a wad of cotton and a one-inch layer of calcium chloride. 3. Under a fume hood, clamp the assembly in a water bath, making sure the assembly is half submerged in the water, and a thermoprobe is clamped in the water as well. 4. Remove the flask assembly and set it aside for the moment. Adjust the hot plate to warm the water bath to 50°C. 5. Take the flask assembly to the chemical supply hood and temporarily remove the drying tube assembly and add 0.4 mL of thionyl chloride (d = 1.63 g/mL) using the attached 1.0 mL cali- brated pipette. Then add 6 drops of dimethylformamide (DMF) to the flask and replace the drying tube. Do this entire step in the chemical supply hood only, do not remove the thionyl chloride bottle or its associated pipette from that hood. 6. Bring the flask back to the hood with your 50°C water bath, clamp the assembly in place and stir the mixture for 10 minutes at 50°C. It is essential to keep the temperature of the water bath at 50° t 5°C. Do not start tining if the temperature is below 45°C. 7. After the flask assembly is warming in the water bath place a 50 mL Erlenmeyer flask contain- ing 12 mL of concentrated ammonia (15 M) in an ice bath in the same hood, close to your water bath. Note: In research labs, often such water-sensitive reactions are performed under an inert atmosphere (argon or nitrogen gas) rather than using a drying tube. 8. If the entire sample has not liquified after approximately 10 minutes, remove the flask assembly from the water bath, take it to the chemical supply hood and add another 0.2 mL of thionyl chloride to the mixture, as before. 9. Bring the flask assembly back to your water bath and continue heating until no solid remains. Continuous stirring also helps to complete the reaction. 10. Once the reaction is complete, raise the reaction flask above the water bath and remove the drying tube. Use an eyedropper to transfer the acid chloride solution dropwise (slowly, at a rate of 1 drop per two seconds) to the ice-cold flask of ammonia while stirring. Keep the ammonia solution in the ice bath during the addition of 3-nitrobenzoyl chloride. REMEMBER TO KEEP YOUR HEAD OUT OF THE EXHAUST HOODS AT ALL TIMES DURING THIS EXPERIMENT. BOTH HCI AND SO, ARE EXTREMELY POISONOUS GASES. 11. Maximum yields are obtained when the addition is performed with cold ammonia, which is stirred continuously. Keeping 1-2 pieces of ice in the ammonia solution during the addition will help keep the temperature close to 0°C. Inverting the eyedropper allows the acyl chloride to enter the rubber bulb, contaminating your product and destroying the rubber. Do not hold an eyedropper upside down. 12. When the addition is complete, rinse the round bottom flask and the eyedropper with some ammonia. The materials may now be safely removed from the hood if the ammonia flask is stoppered. Otherwise, cool it in the hood. 13. Cool the crude amide for a few minutes, and collect the solid by suction filtration on a Hirsch funnel. A 1.5 cm piece of filter paper should just cover the bottom of the funnel, the same as a Büchner funnel. 14. Wash the product well with water to remove a large amount of NH,CI. Pour this ammonia waste down the drain promptly, and rinse with water. 15. Use a 10 mL pear-shaped flask to recrystallize the crude amide by dissolving it in a mini- mum amount of denatured ethanol with heating (1-2 mL depending on the yield of your 3-nitrobenzamide). 16. Then add enough water to just saturate (first cloudiness) the solution followed by addition of 1-2 drops of ethanol. Do not add more than 5 mL of water in any case, as the product is also somewhat soluble in water. 17. The above crystallization is a difficult one to perform successfully. It is always a good idea to keep a few crystals of the crude product for "seeding" in case you have trouble with the recrys- tallization. Remember, also, that a trace of ammonium chloride may be trapped in the crude amide it will be virtually insoluble in denatured ethanol so you may have to filter it. 18. Use your Hirsch funnel to collect the product by suction filtration after cooling the 10 mL pear-shaped flask in an ice bath for five minutes. The mother liquor should be added to the Hazardous Waste Container. 19. If you have not already done so, return the calcium chloride to the solid waste container. Calcium chloride left in drying tubes will eventually form a solid cake that is almost impossible to remove. 20. Simultaneously determine the melting point of the starting 3-nitrobenzoic acid, the final amide, and an intimately ground mixture of the two solids. The amide and corresponding acid both melt near 130°C. The range is from the first appearance of liquid until the complete disappear- ance of solid. It should be quite wide for a mixed melting point. Weight of 3-nitrobenzamide = 0.28 g m.p. of 3-nitrobenzamide = 137.5 °C 1) ΗΝO 2) NaOH OH OCH3 OCH3 H2SO4 3) HCI Experiment 7 & 8 NO2 NO2 Actual Yield % Yield X 100 Theoretical Yield Mass (g) Density %| Volume (mL) Grams Mole = %3D Molecular weight Moles M = Moles = M X Liter Liter 1. Place 0.5 g of well-powdered 3-nitrobenzoic acid and a stirring bar into a 10 mL round bottom flask. (The powdering is best done with a 25 mL Erlenmeyer and smooth surfaced weighing paper.) 2. Attach a drying tube containing a wad of cotton and a one-inch layer of calcium chloride. 3. Under a fume hood, clamp the assembly in a water bath, making sure the assembly is half submerged in the water, and a thermoprobe is clamped in the water as well. 4. Remove the flask assembly and set it aside for the moment. Adjust the hot plate to warm the water bath to 50°C. 5. Take the flask assembly to the chemical supply hood and temporarily remove the drying tube assembly and add 0.4 mL of thionyl chloride (d = 1.63 g/mL) using the attached 1.0 mL cali- brated pipette. Then add 6 drops of dimethylformamide (DMF) to the flask and replace the drying tube. Do this entire step in the chemical supply hood only, do not remove the thionyl chloride bottle or its associated pipette from that hood. 6. Bring the flask back to the hood with your 50°C water bath, clamp the assembly in place and stir the mixture for 10 minutes at 50°C. It is essential to keep the temperature of the water bath at 50° t 5°C. Do not start tining if the temperature is below 45°C. 7. After the flask assembly is warming in the water bath place a 50 mL Erlenmeyer flask contain- ing 12 mL of concentrated ammonia (15 M) in an ice bath in the same hood, close to your water bath. Note: In research labs, often such water-sensitive reactions are performed under an inert atmosphere (argon or nitrogen gas) rather than using a drying tube. 8. If the entire sample has not liquified after approximately 10 minutes, remove the flask assembly from the water bath, take it to the chemical supply hood and add another 0.2 mL of thionyl chloride to the mixture, as before. 9. Bring the flask assembly back to your water bath and continue heating until no solid remains. Continuous stirring also helps to complete the reaction. 10. Once the reaction is complete, raise the reaction flask above the water bath and remove the drying tube. Use an eyedropper to transfer the acid chloride solution dropwise (slowly, at a rate of 1 drop per two seconds) to the ice-cold flask of ammonia while stirring. Keep the ammonia solution in the ice bath during the addition of 3-nitrobenzoyl chloride. REMEMBER TO KEEP YOUR HEAD OUT OF THE EXHAUST HOODS AT ALL TIMES DURING THIS EXPERIMENT. BOTH HCI AND SO, ARE EXTREMELY POISONOUS GASES. 11. Maximum yields are obtained when the addition is performed with cold ammonia, which is stirred continuously. Keeping 1-2 pieces of ice in the ammonia solution during the addition will help keep the temperature close to 0°C. Inverting the eyedropper allows the acyl chloride to enter the rubber bulb, contaminating your product and destroying the rubber. Do not hold an eyedropper upside down. 12. When the addition is complete, rinse the round bottom flask and the eyedropper with some ammonia. The materials may now be safely removed from the hood if the ammonia flask is stoppered. Otherwise, cool it in the hood. 13. Cool the crude amide for a few minutes, and collect the solid by suction filtration on a Hirsch funnel. A 1.5 cm piece of filter paper should just cover the bottom of the funnel, the same as a Büchner funnel. 14. Wash the product well with water to remove a large amount of NH,CI. Pour this ammonia waste down the drain promptly, and rinse with water. 15. Use a 10 mL pear-shaped flask to recrystallize the crude amide by dissolving it in a mini- mum amount of denatured ethanol with heating (1-2 mL depending on the yield of your 3-nitrobenzamide). 16. Then add enough water to just saturate (first cloudiness) the solution followed by addition of 1-2 drops of ethanol. Do not add more than 5 mL of water in any case, as the product is also somewhat soluble in water. 17. The above crystallization is a difficult one to perform successfully. It is always a good idea to keep a few crystals of the crude product for "seeding" in case you have trouble with the recrys- tallization. Remember, also, that a trace of ammonium chloride may be trapped in the crude amide it will be virtually insoluble in denatured ethanol so you may have to filter it. 18. Use your Hirsch funnel to collect the product by suction filtration after cooling the 10 mL pear-shaped flask in an ice bath for five minutes. The mother liquor should be added to the Hazardous Waste Container. 19. If you have not already done so, return the calcium chloride to the solid waste container. Calcium chloride left in drying tubes will eventually form a solid cake that is almost impossible to remove. 20. Simultaneously determine the melting point of the starting 3-nitrobenzoic acid, the final amide, and an intimately ground mixture of the two solids. The amide and corresponding acid both melt near 130°C. The range is from the first appearance of liquid until the complete disappear- ance of solid. It should be quite wide for a mixed melting point. Weight of 3-nitrobenzamide = 0.28 g m.p. of 3-nitrobenzamide = 137.5 °C 1) ΗΝO 2) NaOH OH OCH3 OCH3 H2SO4 3) HCI Experiment 7 & 8 NO2 NO2 Actual Yield % Yield X 100 Theoretical Yield Mass (g) Density %| Volume (mL) Grams Mole = %3D Molecular weight Moles M = Moles = M X Liter Liter
Expert Answer:
Answer rating: 100% (QA)
Based on the provided instructions here are the steps for the chemical reaction setup 1 Take a 10 mL round bottom flask and add 05 g of wellpowdered 3nitrobenzoic acid and a stirring bar 2 Attach a dr... View the full answer
Related Book For
Posted Date:
Students also viewed these accounting questions
-
A student gently drops an object weighing 15.8 g into an open vessel that is full of ethanol, so that a volume of ethanol spills out equal to the volume of the object. The experimenter now finds that...
-
A glass tube is attached to a water pipe, as shown in Fig. P1109, if the water pressure at the bottom of the tube is 115 kPa and the local atmospheric pressure is 92 kPa, determine how high the water...
-
A flask contains 25.0 mL of diethyl ether weighing 17.84 g. What is the density of the ether?
-
(a) Find the acceleration at time t = 5 min of a helicopter whose height is s(t) = 300t 4t 3 m. (b) Plot the acceleration s" for 0 t 6. How does this graph show that the helicopter is slowing down...
-
Why are the legal standards different for criminal and civil matters? Separately identify the differences between these two types of matters from the perspectives of the defendant and the...
-
When are tables of numbers useful in the decision-making process? When are graphs of those numbers useful?
-
To the left of z = 0.26 Find the indicated area under the standard normal curve. If convenient, use technology to find the area.
-
The partnership of Angel Investor Associates began operations on January 1, 2012, with contributions from two partners as follows: Scott Wilson ... $120,000 Michael Goforth .. 80,000 The following...
-
Your text talks about Therapeutic Use Exemptions (TUE) and how they play a role in modern drug testing. You've also read a portion of the Major League Baseball Joint Drug Prevention and Treatment...
-
The goodwill of $20,000 on Illini's 12/31/20X0 Balance Sheet is related to a subsidiary of Illini (i.e., a reporting unit). At the end of 20X1, there is no indication that it is more likely than not...
-
A 200 x 100 x 50 mm steel block is subjected to a hydrostatic pressure of 15 MPa. The Young's modulus and Poisson's ratio of the material are 200 GPa and 0.3 respectively. The change in the volume of...
-
Explain the relationship between dynamic storage allocation and recursion.
-
The following output is possible using a queue: 1 2 3 4 5 1. True 2. False 3. Not enough information to determine
-
Washers used in a certain application are supposed to have a thickness of 2 millimeters. A quality control engineer measures the thicknesses for a sample of washers and tests \(H_{0}: \mu=2\) versus...
-
Given the following values in list: Show the contents of the run-time stack during the execution of this call to BinarySearch: list .length .info 10 2 [0] 6 [1] 9 [2] 14 [3] 23 [4] 65 [5] 92 [6] 699...
-
Show what would be written by the following calls to the recursive function Puzzle: 1. cout int Puzzle(int base, int limit) { } if (base > limit) return -1; else if (base == limit) return 1; else...
-
the company that Kathleen works for recently deployed a SIEM to help with log capture and analysis. One of the SIEM's features is an alerting function for certain types of logged events and...
-
Draw two scatterplots, one for which r = 1 and a second for which r = 21.
-
The cell potential of the following cell at 25oC is 0.475 V.
-
Heavy metal azides, which are salts of hydrazoic acid, HN3, are used as explosive detonators. A solution of 0.20 M hydrazoic acid has a pH of 3.21. What is the Ka for hydrazoic acid?
-
Discuss why supercritical carbon dioxide is a nearly ideal solvent.
-
What is the difference between old classical and new classical economics?
-
What is the difference between traditional Keynesian and new Keynesian economics?
-
Why does monetary policy operate with a long and variable lag? Give an example to illustrate your explanation.
Study smarter with the SolutionInn App