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d for 1H NMR should be dilute.
b. Samples for 13C NMR should be dilute, and for 1H NMR should be concentrated.
c. Samples for 13C NMR and 1H NMR should both be concentrated.
d. Samples for 13C NMR and 1H NMR should both be dilute.
3. What is the proper way to dispose of an NMR sample that had deuterated chloroform (CDCl3) as the solvent?
a. Placement down the drain.
b. Placement in the non-halogenated organic waste container.
c. Placement in the halogenated organic waste container.
d. Placement in the oven for evaporation.
4. Which feature of a 1H NMR spectrum can provide information about the number of inequivalent kinds of hydrogen in the structure?
a. chemical shift
b. coupling
c. integration
d. None of the above.
5. Which feature of a 1H NMR spectrum can provide information about the number of neighboring hydrogens that a given hydrogen in the structure has?
a. chemical shift
b. coupling
c. integration
d. None of the above.
6. Which feature of a 1H NMR spectrum can provide information about the number of hydrogens responsible for each signal?
a. chemical shift
b. coupling
c. integration
d. None of the above
7. An unknown has a specific rotation (i.e., a rotation unequal to 0°) as measured with a polarimeter. What is true about the unknown?
a. The structure contains at least one chirality center.
b. The structure contains no chirality centers.
c. The structure has a plane of symmetry.
d. None of the above.
8. True or False: Conjugation increases the wavenumber of absorption in the IR spectrum.
True
False
9. What group classification does a solid unknown most likely belong to if its melting point is greater than 250 °C?
a. carboxylic acid
b. amino acid
c. amine
d. acid derivative
10. True or False: If a liquid unknown freezes when placed in an ice-water bath for 10 minutes, the melting point of the unknown is between 0 °C and 25 °C.
True
False

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interested in whether or not there is a benefit trying to locate their restaurants in shopping centre food courts.
Food Court Not in Food Court
Average Revenue 1609.69 1710.0
Standard deviation 190.85 150.83
Sample size 12 38
a. Conduct a test at the 5% level of significance to determine if there is a difference in average revenue between restaurants located in food courts to those that aren’t. Make whatever assumptions and carry out any checks that are necessary to conduct this test. (5)

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titrated with a 0.200 M solution of the base, LiOH.
Write the balanced chemical reaction for neutralization reaction:
HClO4 (aq) + LiOH (aq) → LiClO4 (aq) + H2O (l)
Write the NET ionic equation for the neutralization reaction.
OH⁻ (aq) + H⁺ (aq) → H2O (l)
Compute the pH of the titration solution. Show your work
i) before any of the base is added
ii) after 25. mL of base is added
iii) after 50. mL of base is added
A student performs the titration with the same chemicals but with smaller volumes of each chemical . Which of the following titration curves could represent the titration. Explain
A because this entails a strong acid and a strong base.
Question 2
A student performs a titration of an unknown acid with a strong base and gets the following titration curve:
a) The student consults the list of pKa of acids shown below. If the acid is listed in the table below, which is the most likely identity of the unknown acid? Explain.
Acid
Ka
HF
7.2 x 10-4
CH3COOH
1.8 x 10-5
H2CO3
4.3 x 10-7
HBrO
2.0 x 10-9
The unknown acid is HBrO because the calculated Ka is in between 50^-4 and 50^-6 and 2.0 x 10^-9 lies in between them.
b) What is the initial molarity of the acid?
10^-3 = 0.001M
Question 3
a) Describe the components and the composition of an effective buffer solution. Explain how the components of the buffer allow the buffer to maintain its pH.
An effective buffer solution has a weak acid and its conjugate base or a weak base and its conjugate acid. A buffer solution is most effective when the ratio of its component concentrations is close to 1, also when the pH is equal to the pka of the acid.; The components of the buffer allow the buffer to maintain its pH because buffers can absorb excess H+ions or OH– ions.
An employer is interviewing four applicants for a job as a laboratory technician and asks each how to prepare a buffer solution with a pH of 5.0. The following constants may be helpful: hydrazoic acid, pKa = 4.74 Boric acid, pKa = 9.23
Archita A. says she would mix equal molar solutions of hydrazoic (HN3) and sodium azide (NaN3) solutions.
Bradley B. says she would mix equimolar Boric acid (H3BO3) and HCl solutions.
Carlos C. says he would mix equimolar Boric Acid (H3BO3) and sodium dihydrogen borate (NaH2BO3) solutions.
Delia D. says he would mix equimolar hydrazoic Acid (HN3) and NaOH solutions.
b) Which of these applicants has given an appropriate procedure? Explain your answer
Delia because she is using Sodium hydroxide which results in a pH of 5. NaOH is a strong base and in order to have an effective buffer a weak acid must be incorporated which is the HN3.
c) Explain what is wrong with the erroneous procedures.
The rest all incorporate a strong acid and a strong base or a weak acid and a weak base which don’ result in an effective buffer.
d) The applicants have access to the 1 Liter volumes of each of the solutions listed above. They have access to graduated cylinders. In order to make 1.0 Liter of the correct 5.0 buffer solution, what volumes of the two chemicals must be mixed?

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2,3,4,7). If it lands tails, a fair six-sided die is
thrown (with values 3,4,5,6,7,9). Regardless of which die is used, Alice
eats n grains of rice, where n is the largest prime factor of the die result
(for example, the largest prime factor of 9 is 3).
(a) What is the conditional probability that the coin lands heads, given
that Alice eats three grains of rice?
(b) Suppose that the entire experiment is conducted twice on the following day (starting with a new coin toss on the second run-through).
What is the conditional probability that the coin lands heads on both
run-throughs, given that Alice eats a total of five grains of rice during the two run-throughs?
(Do not count the two grains from part (a) in part (b); we assume
two brand new experiments, each with a new coin toss. Start your
solution by defining a suitable partition of the sample space. Please
use an appropriate notation and/or justification in words, for each
value that you give as part of your solution.)
Exercise 5) Alice and Bob throw an unfair coin repeatedly, with probability 2/5 of landing heads. Alice starts with £2 and Bob starts with £3 .
Each time the unfair coin lands heads, Alice gives Bob £1 . Each time
the unfair coin lands tails, Bob gives Alice £1 . The game ends when one
player has £5 .
(a) Draw a labelled Markov chain describing the problem, and write
down a transition matrix P. Write down the communication classes,
and classify them as either recurrent or transient.
(b) Using the transition matrix, calculate the probability that Alice loses
all of her money in exactly four tosses of the unfair coin.
(c) Calculate the (total) probability that Alice loses all of her money
(before Bob loses all of his).
(d) Calculate the expected (mean) number of tosses of the unfair coin,
for the game to end.

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units.
Chemical Equation: Write a generic chemical equation for the dehydration of cobalt (II) chloride ∙ x hydrate (include the state symbols of the reactant and two products). [T2]
Mass of Reactants and Products:
a) Calculate the initial mass of the hydrated cobalt (II) chloride. [T1]
b) Calculate the final mass of the anhydrous cobalt (II) chloride remaining in the cruiio8icible. [T1]
c) Calculate the mass of water given off by the sample of hydrated cobalt (II) chloride. [T1]
Moles of Products:
a) Calculate the moles of anhydrous cobalt (II) chloride remaining in the crucible. [T1]
b) Calculate the moles of water released from the hydrate. {T1]
4. Mole Ratio
a) Create an experimental mole ratio between the b) and a). [T1]
5. Formula of Hydrate: State the chemical formula you have determined for this hydrate.
Round the formula to the closest whole number value for x. [T1]
Discussion/Conclusion Questions: [T6]
Based on the chemical formula of the hydrate, calculate the percentage composition (percent by mass) of the hydrated cobalt (II) chloride. Remember to determine the percentage of each element (Co, Cl, H, and O). [T2]
A possible source of systematic error in this experiment is insufficient heating. Suppose that the hydrate was not completely converted to the anhydrous form. Describe how this would affect: the calculated percent by mass of water and the experimental molecular formula (i.e. would x be higher, lower or the same).
Suppose a student spilled some of the hydrated cobalt (II) chloride. Describe how this would affect the calculated percent by mass of water (would it be higher, lower or the same) and the experimental chemical formula of the hydrate. [T2]

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time a bag of chips remains fresh on the grocery shelf. A random sample of potato chips with the old design of the bag was compared to a random sample of potato chips with the new bag. Summary statistics pertaining to the number of days the chips remained fresh are given below. At a 95% level of confidence (α = .05), the company wishes to investigate if the new bag has an increased freshness time over the old bag.
Summary Statistics
New Bag Old Bag
(Sample #1) (Sample #2)
Sample Mean 21.2 days 20.8 days
Sample Standard Deviation 2.5 days 2.8 days
Sample Size 45 50
What is the correct Null and Alternate Hypothesis?
Select one:
a. H_0: \mu_d>0\;\; H_1: \mu_d < 0
b. H_0: \mu_1>\mu_2 \;\;H_1:\mu_1 \leq \mu_2
c. H_0: \mu_d =0\;\; H_1: \mu_d < 0
d. H_0: \mu_1\leq\mu_2 \;\;H_1:\mu_1 > \mu_2

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eople experienced a group-based behavioral intervention, which involved weekly meetings with a trained interventionist for a period of six months. The following data are the numbers of pounds lost for 14 people, based on means and standard deviations given in the article. Assume the population is approximately normal. Perform a hypothesis test to determine whether the mean weight loss is greater than 20 pounds. Use the =α0.10 level of significance and the critical value method.
22.5 28.5 7.6 24.1 21.5 12.9 17.3
21.2 37.6 33.8 12.1 36.3 24.1 19.4

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, a standard deviation of $1 would be considered large if it is describing the variability from store to store in the price of an ice cube tray. On the other hand, a standard deviation of $1 would be considered small if it is describing store-to-store variability in the price of a particular brand of freezer. A quantity designed to give a relative measure of variability is the coefficient of variation. Denoted by CV, the coefficient of variation expresses the standard deviation as a percentage of the mean. It is defined by the formula CV = 100(s/ x ). Consider two samples. Sample 1 gives the actual weight (in ounces) of the contents of cans of pet food labeled as having a net weight of 8 oz. Sample 2 gives the actual weight (in pounds) of the contents of bags of dry pet food labeled as having a net weight of 50 lb. There are weights for the two samples.
Sample 1 7.7 6.8 6.5 7.2 6.5
7.7 7.3 6.6 6.6 6.1
Sample 2 50.7 50.9 50.5 50.3 51.5
47 50.4 50.3 48.7 48.2
(a) For each of the given samples, calculate the mean and the standard deviation. (Round all intermediate calculations and answers to five decimal places.)
For sample 1
Mean
Standard deviation
For sample 2
Mean
Standard deviation
(b) Compute the coefficient of variation for each sample. (Round all answers to two decimal places.)
CV1
CV2

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d balls for all players is normally distributed with a mean of 87 mph and a standard deviation of 2.5 mph. For any sample of individual batted balls hit by one player, the standard deviation of exit velocity of those batted balls around this particular player's true-talent AEV is 9 mph. At this point in the season, Marco Masher has a total of 10 batted balls with an average exit velocity of 96 mph. Given only this information, the best estimate for his "true talent" exit velocity is closest to which whole number?

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survey of all their employees found that employees were required to respond to an average of 50 work-related emails per week with a standard deviation of 1.5 emails per week. However, an employee advocacy group believes the average number of work-related emails Indigo Insurance Company employees are now required to respond to is more than 50 emails per week.
To investigate this further, the employee advocacy group took a random sample of 20 staff employed by Indigo Insurance Company during the second week of March 2018,and asked these employees to record the number of work-related emails to which they were required to respond.
(b). What does the highlighted section of the distribution in Figure 1 represent?
(c). The random sample of 20 employees of Indigo Insurance Company taken by the employee advocacy group turned out to have a mean of 50.8 work-related emails to respond to in that week. Does this sample look like it belongs to the sampling distribution displayed in Figure 1? Justify your answer.
(d). Given the sample was randomly selected and that the number of work-related emails each employee was required to respond to was recorded accurately, what conclusion can we reach from part (c)?
To answer questions (b) to (d), consider the sampling distribution shown in Figure 1.

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t way to do that would be to investigate her students’ test performance in a number of ways.
The first thing she did was separate her students’ test scores based on the time of day she held her lectures (morning vs evening). Next she recorded the type of test students were writing (multiple choice vs short answer). She selected a random sample of students from her morning (n = 6) and evening (n = 7) classes (total of 13) and recorded scores from two of their tests as shown below.
Morning
Evening
Multiple Choice
Short Answer
Multiple Choice
Short Answer
66
74
70
45
64
55
80
55
72
77
78
55
70
57
84
60
61
58
64
70
67
69
84
60
70
63
DATA Set 1:
Good morning sunshine. Is Time of Day important?
1. Prof. Maya recently read an article that concluded students retained more information when attending classes in the morning. Based on this finding she thought students in her morning class might have performed differently on their Short Answer test scores when compared to students in her evening class. Does the data support her hypothesis? [15 points]
Multiple Guess! Does Exam Type matter?
2. Prof. Maya also knew that students often did better on multiple-choice tests because they only have to recognize the information (rather than recall it). Given this, she thought students attending the morning class might perform differently on the Multiple-Choice test when compared to the Short Answer test. Does the data support her hypothesis? [15 points]
DATA Set 2:
We’ll try anything once. Does the new Tutorial Plan work?
3. Combining all of her students (and ignoring time of day), Prof. Maya asked her TAs to try a new – and very expensive - tutorial study plan. She then chose a random sample of 20 students to receive the new study plan and another sample of 30 to continue using the old study plan. Following an in-class quiz, she divided the students into 3 levels of achievement (below average, average, and above average), and then created the frequency table below. Does the new expensive tutorial study plan improve student performance? [15 points]
Below average
Average
Above Average
New plan
7
7
6
Old plan
6
15
9
DATA Set 3:
How are YOU doing?
4. Finally, Prof. Maya thinks that her 2018 class is doing better than her 2017 class did. She decided to collect a sample of test scores from the students in her course this year (combining all of the groups) and compare the average with her previous year’s class average. Does the data support her hypothesis? [15 points]
The 2017 class average = 63%
The 2018 sample size = 25
The 2018 sample standard deviation = 11
The 2018 sample average = use your actual midterm mark (yes, you the student reading this :)
Bonus: What does it all mean?
5. Bonus: IF Prof. Maya had complete control of how and when she ran her course in 2018, considering all the info you just found in the 3 data sets, write a brief statement of how you would recommend she set-up the course next year – and explain why. [5 points]

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t way to do that would be to investigate her students’ test performance in a number of ways.
The first thing she did was separate her students’ test scores based on the time of day she held her lectures (morning vs evening). Next she recorded the type of test students were writing (multiple choice vs short answer). She selected a random sample of students from her morning (n = 6) and evening (n = 7) classes (total of 13) and recorded scores from two of their tests as shown below.
DATA Set 1:
Good morning sunshine. Is Time of Day important?
1. Prof. Maya recently read an article that concluded students retained more information when attending classes in the morning. Based on this finding she thought students in her morning class might have performed differently on their Short Answer test scores when compared to students in her evening class. Does the data support her hypothesis? [15 points]
Multiple Guess! Does Exam Type matter?
2. Prof. Maya also knew that students often did better on multiple-choice tests because they only have to recognize the information (rather than recall it). Given this, she thought students attending the morning class might perform differently on the Multiple-Choice test when compared to the Short Answer test. Does the data support her hypothesis? [15 points]
DATA Set 2:
We’ll try anything once. Does the new Tutorial Plan work?
3. Combining all of her students (and ignoring time of day), Prof. Maya asked her TAs to try a new – and very expensive - tutorial study plan. She then chose a random sample of 20 students to receive the new study plan and another sample of 30 to continue using the old study plan. Following an in-class quiz, she divided the students into 3 levels of achievement (below average, average, and above average), and then created the frequency table below. Does the new expensive tutorial study plan improve student performance? [15 points]
Below average
Average
Above Average
New plan
7
7
6
Old plan
6
15
9
DATA Set 3:
How are YOU doing?
4. Finally, Prof. Maya thinks that her 2018 class is doing better than her 2017 class did. She decided to collect a sample of test scores from the students in her course this year (combining all of the groups) and compare the average with her previous year’s class average. Does the data support her hypothesis? [15 points]
The 2017 class average = 63%
The 2018 sample size = 25
The 2018 sample standard deviation = 11
The 2018 sample average = use your actual midterm mark (yes, you the student reading this :)
Bonus: What does it all mean?
5. Bonus: IF Prof. Maya had complete control of how and when she ran her course in 2018, considering all the info you just found in the 3 data sets, write a brief statement of how you would recommend she set-up the course next year – and explain why. [5 points]

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13.I was wondering if you could help me step up my chem problems, i'm not sure how to begin ...

estion 1: Draven collected a 1ml sample from a local river. Draven added 99 ml of water to the sample. Draven then took 5 ml of the diluted sample, and determined the 5 ml sample to contained 10 mg of sodium chloride. what is the concentration of sodium chloride in the river?
question 2: how many grams of H2 could be produced when 13 g of H202 decompose?
question 3: how many molecules of carbon dioxide could be produced when 25 ml of a 0.8 M ethanol, c2h60, combusts with 5.18X10^23 molecules of oxygen? the unbalanced equation for the combustion of ethanol is given below:
2ch6O+302-> c02+h20

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is a multiple of three or greater than eight.
A certain game consist of rolling a single fair die and pays off as follows nine dollars for a six, six dollars for a five, one dollar for four and no payoffs otherwise.Find the expected winnings for this game.
A fair die is rolled four times. A 6 is considered success While all other outcomes are failures find the probability of three successes.
A pet store has nine puppies including 4 poodles 3 terriers and 2 retrievers. If Rebecca an errand in that order each select one puppy at random without replacement find the probability that Aaron select a retriever given that from last Rebecca selects a poodle.
Experience shows that a ski lodge will be for (166 guests) if there is a heavy snowfall in December, well only partially full (52 guests) With a light snowfall. What is the expected number of guests if the probability for a heavy snowfall is 0.40? I assume that heavy snowfall and light snowfall are the only two possibilities.
A pet store has six puppies Including two poodles two Terriers and to retrievers. If Rebecca and Aaron in that order each select one puppy random with replacement (They both may select the same one) Find the probability That Rebecca selects a terrier and Aaron selects a retriever.
Three married couples arrange themselves randomly in six consecutive seats in a row. Determine (A) the number of ways the following event can occur, And (B) the probability of the event. (The denominator of the probability fraction will be 6!=720, The total number of ways to arrange six items ). Each man was that immediately to the right of his wife.
A coin is tossed five times. Find the probability that all our heads. Find the probability that at least three are heads.
A certain prescription drug is known to produce undesirable facts and 35% of all patients due to drug. Among a random sample of a patient using a drug find the probability of the stated event. Exactly 5 have undesired effects.
10,000 raffle tickets are sold. One first prize of 1600, for second prizes of 800 each, And 9/3 prizes of 300 each or to be awarded with all winners selected randomly. If you purchase one ticket what are your expected winnings.
Suppose a charitable organization decides to Raise money by raffling A trip worth 500. If 3000 tickets are sold at one dollar each find the expected net winnings for a person who buys one ticket. Round to the nearest cent
Three men and seven women are waiting to be interviewed for jobs. If they are selected in random order find the probability that all men will be interviewed first
A fair diet is rolled. What is the probability of rolling on our number or a number less than three.
The pet store has 15 puppies, including five poodles, five Terriers, and five retrievers. If Rebecca and Aaron, in that order, select one puppy at random without replacement, find the probability that both select a poodle
Beth is taking a nine question multiple-choice test for which each question Has three answer choices, only one of which is correct. Beth decides on answering By rolling a fair die And making the first answer choice if the die shows one or two, The second If the die shows three or four, and the third if the die shows five or six. Find the probability of the stated event. Exactly 6 correct answers
For the experiment of drawing a single card from a standard 52 card deck find (a) the probability and (b) the odds are in favor that they do not drive six

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with a mean of 25 gm and a standard deviation of 5 gm.
(a) If the machine is used 500 times, approximately how many times will it be expected to dispense 30 gm or more of chilli sauce?
(b) How can you decrease this number to half? Give a numerical answer.
2. StarTech manufactures re sensors. They use a protective screen for their sensors to protect it from dust. The sensor becomes useless if the thickness of the screen exceeds 0.5 mm. They outsource the production of the screen to a di erent company that claims to manufacture screens with a mean thickness of 0.3 mm and a standard deviation of 0.1 mm.
(a) If 10000 screens are manufactured how many will be discarded because they are too thick?
(b) If screens less than 0.2 mm are too thin to be used, what is the probability that screens manufactured by the above company will be discarded because they are too thick or too thin? Show the result on a graph.
3. The amount of time that Sam spends playing the guitar is normally distributed with a mean of 15 hours and a standard deviation of 3 hours.
(a) Find the probability that he spends between 15 and 18 hours playing the guitar during a given week.
(b) What is the probability that he spends less than 3 hours playing the guitar during a given week?
4. Soon after he took oce in 1963, President Johnson was approved by 160 out of a sample of 200 Americans. With growing disillusionment over his Vietnam policy, by 1968 he was approved by only 70 out of a sample of 200 Americans.
(a) What is the 90% con dence interval for the percentage of all Americans who approved of Johnson in 1963? In 1968?
(b) What is the 90% con dence interval for the change?

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s, you run the following re- gression on a sample of 65 countries for the year 2012:
books = 8.2314 + (1.0329)
+ 0.3149 age (0.4111)
8.1391 (0.5812)
?
income
4.8121 (0.3543)
+
ereaders,
3.4125 educ (0.7314)
where books is the number of paperback novels purchased in 2012, income is per capita GDP in 2012, educ is the average number of years of education for the population in 2012, age is the average age of the population in 2012 and ereaders is the number of electronic readers (e.g. Kindles) sold in 2012. The numbers in parentheses refer to standard errors corresponding to the estimated coefficients. You also find that R2 = 0.7231 and SSR = 1, 231.
(a) Which of the slope coefficients are statistically different from zero at the 5% level of significance? Perform statistical tests to answer this question. [8 marks]
Solution: Each test carries 2 marks. t ratios are: 14.0039, 4.66, 0.7659, -13.5819. The 2.5% critical value for a tn?k=65?5=60 distribution can be seen to be 2.0000, implying that all coefficients except the one on age are significant.
(b) Does the intercept have a plausible interpretation? Explain briefly. [4 marks]
Solution: The intercept indicates that demand for paperback novels equals 8.2314 when income, educ, age and ereaders all equal zero. Clearly this is not plausible.
(c) Construct a 95% confidence interval for the coefficient on age. [8 marks]
Solution: CI is given by [bage

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1.AU MAT 120 Systems of Linear Equations and Inequalities Discussion

mathematicsalgebra Physics