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Feedback on the summer Chemistry course:

1. By conducting new experiments and obtaining much new knowledge daily, we were able to learn the intricate concepts quicker and collaborate with our peers to facilitate a successful outcome. I really enjoyed blogging and being able to collect all of my assignments on one website. It helped me to stay organized and I was able to submit my lab reports and terms with the click of a button. This improved my study techniques as well. I have greatly benefited from taking summer Chemistry and I do not regret my decision.
2. If I were to tweak or change the course, the only thing I would say is to balance out the homework more. We had a fair amount the entire time, excluding the first night and last week. If the assignments were more spread out, people would be less stressed. I also think it would be helpful to have more specifics of what will be on the exams so that we are positive of what to study.
3. Going beyond The Economist articles through presentations in order to enhance our scientific understanding, we could maybe pair up in groups with similar articles to create a research paper. This would allow us to compare and contrast, while also improving our writing skills.
4. I think that we honestly use our blogs very effectively as it is; however, we could also keep updating the "Terms" page every night. Most people forgot about this section of our blogs until we were reminded, but it would be very helpful when the time comes for the weekly tests.
5. The instructor should check all the homework on the blogs to make sure that people did their work; however, I do not think that he/she needs to read through each and every assignment for the sake of time. Also, if homework is based on effort, then the teacher should just confirm that the students completed their assignments and not cautiously review every word.
6. With a new head of school who is calling for more creativity, even in science, I think that learning Chemistry should include watching more videos and songs in order to memorize the elements and learn concepts more effectively and efficiently.

Blog Question

How has your study of Chemistry helped you understand science and the world of atoms? How has blogging been helpful?
My study of Chemistry has helped me understand science because I am now more aware of atoms, molecules, solutions, units, the periodic table, distillation, and many other important lessons. I also learned about the world of atoms. Molecules contain atoms, which contain a nucleus with protons and neutrons and circling electrons. In CO2, there is 1 carbon atom and 2 oxygen atoms. In H2O, there are 2 hydrogen atoms and 1 oxygen atom. These all contain certain a certain number of protons, neutrons, and electrons. The proton and electron number (which is the same) is on the top right corner of the periodic table and is also the atomic number. The number of neutrons is the atomic weight minus the atomic number. Blogging has been helpful because I now have a collection of all of my work from this summer. I feel that I have achieved so much and gained a huge body of scientific knowledge in such a short amount of time.

Homework Assignment 23

3SCS #1, 3, 6, 13 p. 279 and 3SBS #11, 12 p. 258

1. Repeating units in each structure

• a. Monomer: 1
• b. Dimer: 2
• c. Trimer: 3
• d. Polymer: unlimited

3. Natural polymers: cellulose, starch, nucleic acids, peptides

Synthetic polymers: polyethylene, polypropylene, polyurethane, polystyrene

6. The term "unsaturated" is used to describe alkenes and alkynes because they have other than single bonds within their structures. Alkenes have a double bond and Alkynes have a triple bond.

13. 

11. 

• a. II
• b. III
• c. I
• d. II

12. The other 75% is lost in heat, which is why the engine is so inefficient.

Homework Assignment 22

3SAS #31-38 p. 235 and 3SBS #1-10 p. 258

31. 

• a. Propane, C3H8
• b. Pentane, C5H12

32. The suffix -ane indicates that hexane is an alkane.

33. Yes, each of these molecules is an isomer of the other. They all have of 5 carbon atoms and 12 hydrogen atoms, but appear to be different because of the arrangement of those atoms. These three molecules are structured isomers of one another, for they have identical molecular formulas but different arrangements of atoms.

34. See drawing.

35. Butane (C4H10) is the shortest-chain alkane that can demonstrate isomerism- alkanes with four or more carbon atoms can be demonstrated as straight-chain structures, branched-chain structures, and ring structures.

36. Both representations are correct because of their different arrangements of atoms that do not change the identical molecular formulas of the molecule. This would make the molecules structural isomers of each other.

37.

• a. See drawing.
• b. The branched-chain molecule would have the lower boiling point. Since the straight-chain molecule has greater molecule-to-molecule contact, it has a stronger intermolecular force than the branched-chain molecule, resulting in a higher boiling point.

38.

• a. A short, straight chain would have a lower boiling point because of decreased molecule-to-molecule contact than the longer boiling point. The bonds of this chain would be easier to break than a longer straight chain.
• b. A short, branched chain would have the lower boiling point. Although the bonds of a branched chain are easier to break than those of a straight chain, it would be more difficult to break more molecular bonds within the long chain, resulting in a higher boiling point.
• c. A short, branched chain would have a lower boiling point. Straight chains have stronger intermolecular forces that hold together each molecule in contact; where as bonds between branched chains are more breakable due to the decreased intermolecular molecular forces between them.

1. Petroleum is sometimes considered "buried sunshine" because as a fossil fuel, it originates from biomolecules of prehistoric plants and animals. The energy released by burning petroleum represents energy originally captured from sunlight by these prehistoric green plants during photosynthesis; "buried sunshine".

2.

• a. Potential energy is energy of position, or stored energy ready to be released. An example of potential energy is the energy within an unreleased winded up spring toy.
• b. Kinetic energy is energy related to motion. A car rolling down a hill is an example of kinetic energy.

3. Chemical energy, another form of potential energy, is stored within the bonds in chemical compounds. When an energy-releasing reaction takes place, the bonds break and reactant atoms reorganize to form new bonds and release energy. If more energy is released than originally started with, the reaction is exothermic, but if less energy is released than originally started with, the reaction is endothermic.

4. A molecule of butane has more potential energy; it has more carbons than methane and a higher boiling point than methane. The bonds of butane are harder to break than the bonds of methane, resulting its higher potential energy.

5.

• a. Potential
• b. Potential
• c. Kinetic
• d. Potential
• e. Kinetic

6. Energy is required to break chemical bonds because it is what causes the reactant bonds to break and reorganize to form new bonds and energy.

7.

• a. Exothermic energy is released than is required to begin the chemical reaction.
• b. Endothermic energy is required to crack large hydrocarbon molecules than is released.
• c. Endothermic takes more energy to digest a candy bar than the energy released after digestion.

8. The product of a burning candle yields more energy than the energy to begin the reaction with an unlit candle. Since more energy is let off than required to begin the reaction, burning a candle is an exothermic reaction.

9. See drawing.

10. The law of conservation of energy states that energy is neither created nor destroyed in any mechanical, physical, or chemical processes.

Blog Question

Fossil fuels vs. alternative energy and vehicles. How do hybrid vehicles help the planet? Electric vehicles?
Alternative energy is energy derived from sources that do not use up natural resources or harm the environment, whereas fossil fuels are natural fuels such as coal and gas, formed in the geological past from the remains of living organisms. Hybrid vehicles can help the planet because they come equipped with a gasoline-burning engine as well as a battery-powered electric motor. The batteries recharge as the car drives, through converting kinetic energy into stored chemical potential energy whenever the brakes are on.

Blog Question

Distillation separating alcohol and water.
Steps:

1. Pour the alcohol/water into a distillation flask.
2. Set the flask on a Bunsen burner.
3. Insert the fractioning column into the flask and insert a thermometer into the top of the fractioning column.
4. Connect a condenser to the thinner end of the fractioning column.
5. Put potassium carbonate into the condenser.
6. Put another flask below the condenser that will capture the alcohol.
7. Connect the Bunsen burner to the gas.
8. Light the flame.
9. Adjust the position of the Bunsen burner until the flame is blue.
10. Wait until there is no more liquid coming from the condenser and the flask is mostly alcohol.

Homework Assignment 21

Unit 4 B.3 #1-4 p. 344, Unit 4 B.8 #1-6 p. 350, 3SAS #1-30 p. 233 (except 2, 4, 9, 14, 24, 25)

1. Human exposure to ultraviolet radiation is more harmful than infrared radiation because while infrared is simply heat energy, ultraviolet is a more energetic form of sun radiation. Ultraviolet radiation can cause sunburns and skin cancer, harming many organisms with its ability to break covalent bonds.

2. Two essential roles played by visible solar radiation are that it energizes electrons in some chemical bonds. This supplies energy needed for photosynthesis reactions and the scattering of light in a sunset.

3. Since there is less water vapor, there is less greenhouse gas caused by water vapor in dry and arid regions. Infrared radiation is not as stored and reradiated and reflected back into the atmosphere from the entering of UV and visible light that is transformed into IR radiation in clouds, but the visible and UV radiation directly exposed to the surface of the earth is used to heat earth.

4.

• a. The daytime temperatures would be cooler, because with less greenhouse gases such as CO2 and H2O, less infrared radiation would be stored and reradiated and reflected back into the atmosphere from the transformation of UV and visible radiation to IR radiation in clouds Less stored heat energy would enter throughout the day.
• b. Without stored heat energy in the atmosphere, nights would be very cold without the presence of the sun.

1. The mass of carbon dioxide produced daily by all 10 Riverwood High School buses is 1 kg.

2. 0.40 L of fuel are consumed daily by buses idling at Riverwood High School.

3. In a 180-day school year, 180 kg of carbon dioxide would be released into the atmosphere by these buses while idling. 72 L of fuel would be consumed.

4. Atmospheric CO2 levels have increased by about 30% since 1800 due to clearing forests, combustion of cuttings and scrap timber, and the burning of fossil fuels.

5. No, because enough fossil fuel gas is produced naturally on its own.

6. The school bus-idling policy may seem necessary to some people in order to preserve the atmosphere and prevent pollution.


1. A hydrocarbon is a molecular compound that contains carbon.

3. Petroleum is a valuable resource because a small amount contains a large amount of energy. It also creates plastics and polymers.

5. Oil is crude because it is pumped from underground and cannot be used in its natural state without some degree of refinement where it is separated into simpler mixtures through distillation.

6.

• a. 0.11 x 20,000,000= 2,200,000 barrels
• b. 0.89 x 20,000,000= 17,800,000 barrels

7.  Heating and cooking fuel, petrochemicals, kerosene, refined oils, gas oil, heavy furnace oil, diesel fuel oil, lubricating oil and grease.

8.

• a. Water bottle, sports equipment, clothing, and artificial limbs.
• b. A water bottle can be made out of aluminum, bamboo can be used to make light, flexible, and durable sports equipment, clothing can be made of cotton, and artificial limbs can be made of iron.

10.

• a. The Middle East has the most petroleum reserves relative to its population.
• b. Central Asia, Far East, and Oceania have the least petroleum reserves relative to its population.

11.

• a. North America, Central Asia, Far East, and Oceania, Western Europe, and Eastern Europe consume a greater proportion of the world’s supply of petroleum than they possess.
• b. The Middle East, Africa, and Central and South America consume a smaller proportion of the world’s supply of petroleum than they possess.

12. Density can be used to separate two different liquids if the substances are insoluble.

13. Water and acetone would be the easiest to separate from each other by distillation because water has the highest boiling point, and acetone has the lowest of the four substances, water and acetone would separate fairly quickly and easily by distillation.

15. 

16. Fractional distillation differs from simple distillation because fractional distillation does not separate each substance in crude oil. Instead, it produces many different mixtures called fractions. Fractional distillation is a continuous process that consists of a distillation column and various temperatures in order to separate solutions. Simple distillation only involves a apparatus and separates a solution using evaporation and condensation.

17. Products derived from light include motor gasoline and refined oil. Products derived from intermediate include gas oil and heavy furnace oil. Products derived from heavy include lubricating oil/grease and heavy oils/wax.

18. The highest boiling point in a distillation column would most likely be removed at the bottom because the thick liquids never vaporize.

19. After fractional distillation, a way to further separate the mixtures is distillation.

20. Methane, pentane, hexane, octane. The higher the boiling point is, the stronger the intermolecular forces.

21. A covalent bond is the sharing of 2 or more valence electrons between 2 atoms, allowing both atoms to completely fill out their outer shells.

22. Atoms with filled electrons (8 valence electrons) are particularly stable, and therefore, tend to be chemically uncreative. Noble gases are atoms with filled outer electron shells.

23. Since the two dogs desire the sock, they must share it, although they desire to have it for themselves; like repelling electrons, the dogs pull away from each other, but are still connected by the bond they share with the sock connecting them.

26.

• a. A structural formula shows the makeup of a molecule, as well as how high the boiling point is, where as a molecular formula just shows the amount of atoms each element in the formula possesses.
• b. The structure of a formula shows how strong molecular bonds within the formula is, as well as the boiling point of the formula.

27. See drawings.

28.The electron-dot representation of a carbon atom only shows four dots because the four dots represent the valence electrons, located on the outer (and not inner) shell of the atom, where two electrons are located.

29.

• a. C9H20
• b. C16H34
• c. C10H22
• d. C18H38

30.

• a. 128g
• b. 226g
• c. 142g
• d. 254g