1ld quiz 3 sesh 2

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10/28/22, 1:59 AM Quiz #3 Session #2: Chem 1LD F22 https://canvas.eee.uci.edu/courses/48271/quizzes/235276 1/9 Quiz #3 Session #2 Due Nov 2 at 11:59pm Points 10 Questions 11 Time Limit None Allowed Attempts 3 Instructions Attempt History Attempt Time Score KEPT Attempt 2 3 minutes 10 out of 10 LATEST Attempt 2 3 minutes 10 out of 10 Attempt 1 12 minutes 9.67 out of 10  Correct answers are hidden. Score for this attempt: 10 out of 10 Submitted Oct 28 at 1:58am This attempt took 3 minutes. The information needed to answer these questions can be found in your general chemistry lecture textbook, the Lab Safety for Chemists online text (Sections 6.1.1) and in documents hyperlinked within the project document. Take the Quiz Again 1 / 1 pts Question 1 If a solid does not melt when placed in a capillary in a Digi-Melt, which of the following assumptions may be true? The Digi-Melt doesn't go up to a high enough temperature to melt the solid

10/28/22, 1:59 AM Quiz #3 Session #2: Chem 1LD F22 https://canvas.eee.uci.edu/courses/48271/quizzes/235276 2/9 No information can be found by taking a melting point of this compound The chemical doesn't have a liquid state The Digi-Melt is broken 1 / 1 pts Question 2 Answer 1: Answer 2: The same extract mixture was spotted on three TLC plates and then each plate was developed in a different eluent mixture. Which plate demonstrates the best separation of the mixture? #2 Which eluent mixture was the most polar? [ Select ] Which eluent mixture has an intermediate polarity (relative to the polarity of the other two mixtures)? [ Select ] #2

10/28/22, 1:59 AM Quiz #3 Session #2: Chem 1LD F22 https://canvas.eee.uci.edu/courses/48271/quizzes/235276 3/9 Answer 3: #1 #2 1 / 1 pts Question 3 Which of the following results indicates the product of the synthesis is vanillic acid? (Note: The actual result may or may not be vanillic acid.) Rf from TLC is same as vanillic acid TLC from Fundamental Skills solid melted below 100 degrees C solid is soluble in water melting point is above the DigiMelt range solid had a vanilla odor 1 / 1 pts Question 4 If vanillic acid is the product of the reaction between vanillin and hydrogen peroxide, the reduction half reaction is A the oxidation half reaction is F A. H O + 2H + 2e- 2H O B. 2H O H O + 2H + 2e- C. H O H O + O D. 2 C H O 2 C H O + O 2 2 + 2 2 2 2 + 2 2 2 2- 8 8 3 8 8 4 2

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10/28/22, 1:59 AM Quiz #3 Session #2: Chem 1LD F22 https://canvas.eee.uci.edu/courses/48271/quizzes/235276 4/9 Answer 1: Answer 2: E. C H O + 2H + 2e- C H O + H O F. C H O + H O C H O + 2H + 2e- 8 8 4 + 8 8 3 2 8 8 3 2 8 8 4 + A F 1 / 1 pts Question 5 Answer 1: Answer 2: If divanillin is the product of the reaction between vanillin and hydrogen peroxide, the reduction half reaction is A the oxidation half reaction is D A. H O + 2H + 2e- 2H O B. 2H O H O + 2H + 2e- C. H O H O + O D. 2 C H O C H O + 2H + 2e- E. 2 C H O C H O + 2O F. C H O + 2H + 2e- 2 C H O 2 2 + 2 2 2 2 + 2 2 2 2- 8 8 3 16 14 6 + 8 8 3 16 14 6 2- 16 14 6 + 8 8 3 A D

10/28/22, 1:59 AM Quiz #3 Session #2: Chem 1LD F22 https://canvas.eee.uci.edu/courses/48271/quizzes/235276 5/9 0.5 / 0.5 pts Question 6 Match the role to the chemical vanillin limiting reagent acetic acid source of H+ for redox b hydrogen peroxide oxidizing agent horseradish peroxidase catalyst 2 / 2 pts Question 7 A student combined the following and stirred the solution for 10 minutes: 1.031 g of vanillin 2.20 mL 0.010 M acetic acid 9.0 mg horseradish peroxidase 7.5 mL of 3% H O The precipitate which formed was collected by vacuum filtration and dried in the oven. Once the solid reached room temperature it is massed. Answers should have the correct number of significant figures and no units (omit "g" or "%" from the answers). What is the theoretical yield (in grams) of vanillic acid? 1.139 2 2

10/28/22, 1:59 AM Quiz #3 Session #2: Chem 1LD F22 https://canvas.eee.uci.edu/courses/48271/quizzes/235276 6/9 Answer 1: Answer 2: Answer 3: Answer 4: Answer 5: Answer 6: of divanillin? 1.024 If 0.856 g of product is collected, what is the percent yield of vanillic acid? 75.2 of divanillin? 83.6 If the mass of the product is 1.374 g, the product is still wet and needs to be returned to the oven . 1.139 1.024 75.2 83.6 wet oven 0.5 / 0.5 pts Question 8 Match the following risk terms to their definitions.

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10/28/22, 1:59 AM Quiz #3 Session #2: Chem 1LD F22 https://canvas.eee.uci.edu/courses/48271/quizzes/235276 7/9 hazard potential source of dang risk probability of suffering h risk level hazard severity x expos risk assessment identification of sources risk management wearing personal protec 0.5 / 0.5 pts Question 9 What are the factors that affect the probability of a lab accident? how other people behave how risk is managed how chemicals are used how the physical environment is controlled what type of laws are enforced 0.5 / 0.5 pts Question 10

10/28/22, 1:59 AM Quiz #3 Session #2: Chem 1LD F22 https://canvas.eee.uci.edu/courses/48271/quizzes/235276 8/9 Which of the following must be assessed to reduce the probability of exposure to a hazard? type of personal protective equipment (goggles, gloves, lab coats, etc) needed personal knowledge of the hazards amount of chemical used containment of chemicals (capping reagents, using chemicals in the fume hood) routes of exposure (skin, eyes, inhalation, ingestion) 1 / 1 pts Question 11 Use Table 6.1.1.3 in the laboratory safety text to help answer this question. While pouring 1 M of an aqueous potassium permanganate solution from a 1L reagent bottle, a student's hand slipped and the bottle fell and broke open. A small amount of solution splashed onto the student's eyes. The solution also spilled across the bench top and dripped down to create a pool on the floor. If no safety precautions are followed the severity of the hazard is [ Select ] and the probability of the event happening is [ Select ] . This leads to a risk level that is [ Select ] .

10/28/22, 1:59 AM Quiz #3 Session #2: Chem 1LD F22 https://canvas.eee.uci.edu/courses/48271/quizzes/235276 9/9 Answer 1: Answer 2: Answer 3: Answer 4: Which measure should be taken to manage the risk? [ Select ] moderate possible medium all of these Quiz Score: 10 out of 10

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