answer

watching

views

10 Nov 2019

Help on calculations. Starting at #1

Please show what formula was used and how you calculated your answer.

Please and ThankYou

2. Obtain a sample of Cuso, s HO from your tray or on a weighing paper 3. Weigh 4. Pla your tray or instructor. Weigh, to Â± 0.001 g 1.500 g an empty evaporating dish on the same balance. . sample ace the weighed sample in an weighed sample in an evaporating dish and heat vigorously on a hot plate. Note any colex change 5. Stop heating after 5-10 minutes of vigorous heating. Let the product and the dish cool. 6. W 7. Repeat steps 5-6 until 8. After successive weight agreement record this weight. 9. Using the weight of the empty evaporating dish calculate the weight of the prodact eigh the new "cold" dish and its contents. t steps 5-6 until successive weights of dish plus sample give the same results 10. Proceed to the calculations after the data table. A. Data acquisition: 1. Wt of evaporating dish 31.410 2. Wt of evaporating dishCuso, sHe 38.112 0.978 Wt of Cuso, product after heating B. Calculations 1. Using stoichiometry and the reaction equation, calculate the weight of product theoretically 2. Compare this theoretical weight to the experimental weight obtained in part A above. 3. Are both the theoretical and experimental weights of the products the same? If not 4. Give reasons why both weights are not the same. 5. Calculate the % product in the original Cuso,SH20 sample. 6. Calculate the mass of water produced obtainable from the starting weight of Cuso 5 H,O. calculate the % error of your experimental weight compared to the theoretical weight Calculate the % of H2O in the sample. 8. Does the % H2O agree with the theoretical % H2O indicated by the formula Cuso,5%O? Tabulate your results clearly.

answer

watching

324

views

For unlimited access to Homework Help, a Homework+ subscription is required.

You have 0 free answers left.
Get unlimited access to 3.8 million step-by-step answers.

Get unlimited access

Already have an account? Log in

Hubert KochLv2

22 Aug 2019

Unlock all answers

Get 1 free homework help answer.

Already have an account? Log in

Join us on Discord

Chemistry Study Group

Join now

Related questions

Calculations for CuSO4â¢5H2O

Starting at #1. Using stoichiometry and the reaction equation, calculate the weight of the product theroretically obtainable from the starting weight of CuSO4â¢5H2O.

#2. Compare this theoretical weight to the experimental weight obtained in part A above.

#3. Are both the theoretical and experimental weights of the product the same? If not calculate the % error of your experimental weight compared to the theoretical weight.

#4. Give reasons why both weights are not the same

#5 Calculate the % product in the original CuSO4â¢5H2O sample

#6. Calculate the mass of water produced

#7. Calculate the percnt of H2O sample

#8. Does the % H2O agree with the theoretical % H2O indicated by the formula CuSO4â¢5H2O?

C. Tabulate your results clearly

Question: For the following two experiments I have been asked to find at least 1 procedural change for each that could be made to improve the yield of my product. Please review the experiments and aid me in determining what this change might be. Thanks in advance!

Reduction of Benzophenone

1. In a 50 mL Erlenmeyer flask, dissolve 2.0 g benzophenone in 10 mL of methanol. Also add a stirbar to magnetically stir the solution.

2. Place your solution in an ice bath until the temperature has dropped to 10 C.

3. While your flask is in the ice bath, add 0.42 g of sodium borohydride, in small portions, over a 5 min period. The addition of sodium borohydride is exothermic, so you must take care to add it slowly to keep the temperature under control. This means adding the hydride in 5-6 portions, with about 1 min in between additions.

4. Once the addition of NaBH4 is complete and the vigorous bubbling has ceased, allow the solution to stir at room temperature for 10 minutes.

5. Carefully clamp the Erlenmeyer flask into a 80Â°C water bath and allow it to sit in the hot water bath for 2 minutes.

6. Remove the solution from the hot water bath and allow it to cool to room temperature and then cool it in an ice bath.

7. SLOWLY add 30 mL of cold water and then SLOWLY(dropwise) add 1.4 mL of 6M HCl. Use litmus paper to confirm that your solution is acidic. If your solution is not acidic, add more HCl until it is acidic. You should see the formation of a white precipitate at this point.

8. After adding the HCl, remove your solution from the ice bath and let it stir at room temperature for 20 minutes.

9. Collect the product by suction filtration, washing with 10-25 mL of cold water.

10. Allow the product to completely dry under suction and then record the crude weight.

11. Analyze the purity of your crude product by running a TLC. Dissolve a very small sample of your crude product and the benzophenone starting material in diethyl ether. Spot these samples on two separate lanes of your TLC place and develop the TLC pate with 9:1 petroleum ether: ethyl acetate.

12. If you are convinced that your crude sample is pure diphenylmethanol, record the final mass and run a melting point.

13. If you think some impurities are still present in your crude mixture, recrystallize your product with a minimal amount of hot hexanes. Review your notes from earlier in the semester if you donât remember the steps to run a recrystallization.

14. Record the mass and melting point of your purified diphenylmethanol and place it in a labeled vial to turn in to your instructor.

Oxidation of Diphenylmethanol

1. Place approximately 300-mL of hot (from the tap) water in a 400-mL beaker, add a boiling stone, and place it on a hot plate. Heat the water until it is 90-95 oC. It is important to keep the temperature just below 100 oC; thermal decomposition of the permanganate may occur at higher temperatures resulting in the release of toxic fumes.

2. While your water bath is heating, place 4.82 mmol of diphenylmethanol in a 10- or 25- mL round-bottomed flask.

3. Weigh out approximately 4 grams of the oxidant mixture of KMnO4/CuSO4â¢5H2O.

4. If the temperature of your water bath has reached 90-95 oC, combine the oxidant with the diphenylmethanol in your round-bottomed flask.

5. Vigorously stir the mixture with a microspatula for 5-10 min until the flask is warm to the touch. A color change from purple-blue to brown/black should be observed as you are stirring the solids. This is an indication that a reaction is occurring.

6. When the flask is warm, equip the reaction vessel with an air condenser and clamp it in the hot water bath. Be sure that the solid reaction mixture is below the surface of the water.

7. Heat the reaction for 1 h. Continue to monitor the temperature of the water; if the temperature increases close to 100 deg C, add a bit of cold water to keep the temperature 90-95 deg C and lower the heat setting on your hot plate.

8. After 1 h of heating, remove the flask from the hot water and allow it to cool to room temperature. Remove the reflux condenser.

9. Add 10 mL of hexanes to the solid and stir to mix. Remove the hexanes with a pipette and place it into a 25-mL Erlenmeyer flask. Repeat and combine the extracts.

10. Dry the combined hexane extracts with Na2SO4; decant/filter the hexanes into a preweighed 25-mL Erlenmeyer flask; and evaporate the hexanes using a gentle stream of air.

11. Analyze the purity of your crude product by running a TLC. Make samples of the following for TLC: stock benzophenone, crude benzophenone, and benzhydrol. Spot these samples on three separate lanes of your TLC place and develop the TLC pate with 5:1 hexane/ethyl acetate.

12. If you are convinced that your crude sample is pure benzophenone, record the final mass and run a melting point.

13. If you think some impurities are still present in your crude mixture OR if your product is not a solid, recrystallize your product with a minimal amount of hot methanol or methanol/water. Review your notes from earlier in the semester if you donât remember the steps to run a recrystallization.

14. Record the mass and melting point of your purified benzophenone and place it in a labeled vial to turn in to your instructor.

Weekly leaderboard

Home

Homework Help 3,900,000

Chemistry 830,000

Unlock all answers

Related textbook solutions

Basic Chemistry

Principles of Chemistry Molecular Approach

Principles of Chemistry Molecular Approach

Chemistry: Structure and Properties

Chemistry: A Molecular Approach

Chemistry: A Molecular Approach

Principles of Chemistry: A Molecular Approach

Chemistry: The Central Science

Related questions

Weekly leaderboard