Category: Chemistry

What is the advantage and disadvantage of simple and fractional distillation? How the identity and ratio of unknown compounds were identified by distillation

Simple and Fractional distillation
1. Introduction (2pts)
2. Experimental condition (1pt)
3. Data (4pts)

Data table for simple and fractional distillation your unknown mixture

In one window, show the simple and fractional distillation graphs with line graph format •The relative ratio of unknown compounds

Name and ratio of two of unknowns in your mixture.
Results and Discussion (5pts)

Discuss what is distillation

What is the advantage and disadvantage of simple and fractional distillation?

Compare the simple and fractional distillation with respect to your unknown

How the identity and ratio of unknown compounds were identified by distillation

5. Conclusion: (2pts)
6. References (1pt)
7. Questions ( 5 pts)

A mixture of two miscible liquids with a widely different boiling point is distilled. The temperature of distilled liquid is observed to plateau and then drop before rising again. Explain the temperature drop. (2 points)

One mole of compound A, with vapor pressure 420 mmHg at 50 oC, mixed with 5 moles of compound B, with vapor pressure 480 mmHg at 50 oC to form a homogeneous solution. What is the vapor pressure of mixture at 50 oC? (3 points)

Uses What qualities of the element make it useful for this purpose?Use the Internet (Google image search) find two images. Print the page using a colour printer and cut the images out. Describe each image.

Meet the element-Hydrogen)

If you had a pure sample of the element (no other elements mixed in), describe its appearance in three ways:
1.
2.
3.

Find two facts about the history of the element. (Examples: who discovered it, how was it discovered, where was it discovered)
1.
2.
Name of element. The “numbers” on the
element go below (see notes).
Symbol of element. Include the atomic
number (to the top left) and atomic
weight (to the bottom left) of symbol.
Pictures of things made from the
element, as well as text about the
element get added around pictures.
Element chosen:
USES

Find and describe three things that the element is used for. These might be specific objects (e.g.

x-ray tubes), as well as more general things (e.g. computer technology.) Write down enough descriptive information that you will be able to expand on this in your poster.

Uses What qualities of the element make it useful
for this purpose?
1.
2.
3.
1
2.
3.
IMAGES
Use the Internet (Google image search) find two images. Print the page using a colour printer and cut the images out. Describe each image:

 Why is this considered a “green” oxidation? You may want to compare this oxidation method with others in your textbook (2 pts) Could optical rotation be used to determine the relative amounts of borneol and isoborneol in the product mixture? Explain why or why not (3 pts)

 As you watch the video create bullet point procedural list (3 pts)

Complete the table below. Show all calculations (5 pts)

mmoles (1S)-Borneol mmoles Sodium Chloride mmoles Oxone® Theoretical yield of product Crude % yield

Why is this considered a “green” oxidation? You may want to compare this oxidation method with others in your textbook (2 pts)

Write the balanced equation for the reaction performed. (2 pts)

Star all stereogenic centers (chiral carbons) in the borneol starting material and camphor product. (2 pts)

Why does the carbonyl stretching frequency in the infrared spectrum of camphor occur at 1740 cm-1 whereas that of acetophenone (C6H5COCH3) is found at 1680 cm-1 and that for hexanone is found at 1720 cm-1 (3 pts)

Name three ways you could distinguish your product from the starting material. Name the technique and the observations that your would use to make the distinction. (3 pts)

Part 2 Reduction:

This experiment involves the use of a reducing agent (sodium borohydride) for converting a ketone (camphor) to a secondary alcohol (isoborneol) as illustrated in the second step of the two-step oxidation/reduction sequence shown below. The spectra of borneol, camphor, and isoborneol will be compared to detect structural differences and to determine the extent to which the final step produces a pure alcohol isomeric with the starting material.

In principle, the reduction of camphor can give two diastereomeric alcohols, corresponding to reaction of borohydride at the two faces of the C=O bond. Reaction at the top (“exo”) face regenerates the original starting material, borneol. Reaction at the bottom (“endo”) face yields the other diastereomer, isoborneol. You will use NMR to determine the preferred product

Watch the second video

As you watch the video create bullet point procedural list (3 pts)

Complete the table below. Show ALL calculations (3 pts)

mmoles (1S)-Camphor mmoles NaBH4 Theoretical yield of product Mass of product Crude % yield

Below are NMR spectra of the reduction product obtained using LiAlH4 as a reducing agent. Use this data to calculate the relative proportions of the two isomers. (2 pts)

This is the same data for the reduction using NaBH4 as the reducing agent. The picture is not as pretty but the integrations are shown. Calculate the relative portions of the two isomers. (2 pts)

Could optical rotation be used to determine the relative amounts of borneol and isoborneol in the product mixture? Explain why or why not (3 pts)

Why is argon used to displace the air in the reaction apparatus for the hydroboration step?Briefly describe how GC (gas chromatography) separates the compounds in the crude mixture. Based on this, why does 1-octanol have a higher retention time than 2- octanol?

lab 1 organic chem 2

Calculation of Masses of Reactants. Where applicable, use the volume and the literature density of a liquid reactants to calculate the masses used – look up
the literature value for density, where needed. (2pts)

Calculation of Moles of Reactants and Product. Calculate moles for each reactant and the product. Molar masses can be calculated from the molecular formula and/or looked up. (3 pts)

Percent Yield Calculation. Based on moles of reactants and the stoichiometry of the reaction, determined the limiting reactant, and theoretical yield in moles. Then determine the percent yield for the reaction.

Discuss the regiochemical and stereochemical outcomes of the hydroboration/oxidation reaction. Include a complete curved arrow mechanism for both the hydroboration step and the oxidation step.What is the purpose of using a flame-dried apparatus and a drying tube during the
hydroboration reaction? What undesired reaction will occur if water is present?

Why is argon used to displace the air in the reaction apparatus for the hydroboration step? (2 pts)

Briefly describe how GC (gas chromatography) separates the compounds in the crude mixture. Based on this, why does 1-octanol have a higher retention time than 2- octanol? (3 pts)

Show the first step in the mechanism for hydroboration E-3-methylpent-2-ene, including the transition state. You don’t have to show the mechanism for the oxidation steps, but provide the alcohol (major product) produced after oxidation. (3 pts)

How variable is this between teeth? What is the total surface area available? How flat are these surfaces? how do the teeth compare? How does the estimated bite force compare?

Advancing Chemistry

What do these graphs tell you about the evolution of brain volume? What questions does this raise? How would you frame these as hypotheses? How would you test them? How would you measure tooth size? Should this be done relative to the skull size?

For your skull, measure the occlusal (flattened top) areas of the post canine teeth. How variable is this between teeth? What is the total surface area available? How flat are these surfaces? how do the teeth compare? How does the estimated bite force compare?

What do these observations tell you about the diet? Again, what questions does this raise, and how would you frame them hypotheses and test them?

 Discuss if the food items were a good energy source for you. If not, discuss why not. Foods differ in their density of a wide variety of nutrients as compared to just the calories they give you.

Energy and nutrition projects

For this assignment begin by reviewing Chapter 1, 2 and 3.

Create an “Introduction” section. In the first paragraph of this introduction, briefly describe the purpose of this assignment. Also write a brief paragraph(s) that addresses the following questions:
a. Are you currently on a diet now or have ever been on one? Add a description if so about the general type of diet.
If you’ve been on a diet, did you do any calorie counting or take into consideration the energy of the food you were eating? If so, what was your method?
Did you ever take into account how much exercise you’d have to do to burn off a certain meal or indulgence? If so, how did you calculate that?

Using your notes or your diary of all the foods you ate in one meal. Tell us if it was breakfast, lunch, or dinner. The meal needs to include at minimum 3 food items. List the food items you ate during that meal along with their amounts (or serving size). Include a picture of all the food items. You can create a table similar to the below:

Meal:
Food item
(image) Amount/Serving size Image of Nutritional Information

Review the Nutritional Facts for food each item.
a. If it is available, take a picture/include of each Nutritional Fact Label and insert it as a figure in your Word Document. Make sure it is properly titled.

If your food item does not have Nutritional Fact Label, research what the food item’s nutritional facts are. You are mainly looking for Carbohydrates, Fat and Protein. Include a picture or weblink on where you found the information. For example, McDonalds has a weblink that will calculate nutritional values of their food items. Example:

You will be creating tables and a calculation section for what goes into your tables. Make sure to label all columns and rows. All other calculations can be shown with the individual questions below.
Create a table for your food items showing the “Composition and Energy Content” listing the energy value for each food type (mass of Carbohydrate, Fat and Protein) along with the total Energy. Example shown below.
Table 3.7 shows the energy values for food obtained from burning 1g of carbohydrate, fat, or protein in kilocalories or kilojoules.

Food Carbohydrate (g) Fat (g) Protein (g) Total Energy (kcal)

Total Energy for entire meal __________

Using Table 3.7, calculate the total kilocalories for each food type in this meal (round off the kilocalories to the tens place) and fill in your table. Then calculate the Energy in kilocalories for each food type based on amount of mass, along with the total energy for the entire meal.
See example table below (but do not show your calculation inside your table, only the result).

Example for snack crackers (NOTE – there is a typo in your eText):

FOOD ITEM SNACK CRACKERS
Energy Content Mass (g) x Energy Value = Energy

Carbohydrates(g) 19 g x 4 kcal/1g = 76 kcal
Fat(g) 4 g x 9 kcal/1g = 36 kcal
Protein(g) 2 g x 4 kcal/1g = 8 kcal
Total Energy = 76 kcal + 36 kcal + 8 kcal = 120 kcal

Based on the total energy for the entire meal, use Table 3.9 to determine
a. What percentage of your typical energy requirements you consumed. (Show your full calculation)

How much more of the Typical Energy Requirements for Adults you have left for the day based on your Gender, Age and Activity level.

Using Table 3.10, determine the number of hours of sleep needed to burn off the kilocalories of this meal. (Show calculations.)

Using Table 3.10, determine the number of hours of swimming needed to burn off the kilocalories of this meal. (Show calculations.)

Create a Conclusion section, make sure to put it in your own words, paraphrasing and summarizing. Only use quotes when necessary, citing all sources used.

Summarize the major findings you found above. How did your Total Energy for this meal compared to Typical Energy? How long would it take you to burn off the energy you consumed – looking at how many hours of sleep and swimming was needed to burn off your Total Energy for this meal.

Discuss if the food items were a good energy source for you. If not, discuss why not. Foods differ in their density of a wide variety of nutrients as compared to just the calories they give you.

Explain why you chose each of these food sources and if you would select differently next time. If you were on a particular diet how would your meal fit into that diet. You may have selected the food for other reasons. The foods you select will contain the same classes of biomolecules that you read about in your textbook: carbohydrates, lipids, proteins, nucleic acids, vitamins, and minerals.

Give any final thoughts about this meal and if you would do anything differently next time. Explain.

What is science? More specifically, what makes something science? How is science distinguished from non-science or pseudoscience?

Nature of science

What is science? More specifically, what makes something science? How is science distinguished from non-science or pseudoscience?

These questions have been the source of debate for many centuries, even millennia. Two thousand years ago, natural philosophers disputed the very nature of matter. Was matter continuous, infinite, and divisible as claimed by Plato, Aristotle, and their contemporaries? Or was matter discontinuous, finite, and indivisible, so that a certain smallest, most fundamental unit could be attained, as claimed by Leucippus, Democritus, and few others. Over 2000 years ago, Leucippus coined a term for this fundamental and smallest unit of matter – atomos, yet these ideas were largely ignored for millennia.

What makes one statement or claim science? Along these lines, how do you distinguish a scientific claim from a non-scientific claim, or pseudoscience?

What is the toxicity mechanism of this contaminant (who do is affect, does the toxicant act at the molecular, cell, tissue or organ level, is the toxicity lethal or sublethal…).

Tetrachloroethylene

How does the contaminant move throughout the environment and where is it primarily found (air, water, soil, sediment…)

What organisms are exposed to this contaminant and and how is it taken up by the organism (dermal, inhalation, food….)

Does this contaminant bioaccumulate? If so, what are the factors that influence this bioaccumulation?

What is the toxicity mechanism of this contaminant (who do is affect, does the toxicant act at the molecular, cell, tissue or organ level, is the toxicity lethal or sublethal…).

Describe the effect of this contaminant at the population and ecosystem level.

Are there any regulations in place for this contaminant?