Monday, July 22, 2013

Homework Due Tuesday July 23rd


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



Unit 4 B.3 (p.344) #1-4
1. Human exposure to ultraviolet radiation is potentially more harmful than exposure to infrared radiation because too much exposure to ultraviolet radiation can cause a very bad sunburn that can potentially lead to skin cancer.

2. Two essential roles played by visible solar radiation:
     1. they can energize electrons in some chemical bonds
     2. this provides  energy needed for photosynthesis reactions

3. Dry, arid regions in the United States experience wider air-temperature fluctuations from night to day then do more humid states because there is less water vapor; therefore infrared radiation isn't stored, reradiated, or reflected back into the atmosphere from electromagnetic radiation that is transformed in the clouds to produce infrared radiation. However, heat does reach the earth.

4. a. Day time temperatures would be affected if Earth had less dense atmosphere because it would be colder. This is because with less greenhouse gasses, like CO2 or H2O, less infrared radiation would be absorbed and be reflected back onto the atmosphere from the UV and visible radiation that was transformed to IR radiation in the clouds. In all less heat energy would be formed from less absorbed infrared radiation.
    b. The night time temperatures would be affected if Earth has less dense atmosphere because it would be colder than it would normally be because one there is no presence of the sun and two because less infrared radiation is absorbed and reflected back onto Earth, making it colder.

Unit 4 B.8 (p.350) #1-6
1. 1kg of carbon dioxide is produced daily by all 10 Riverwood High School buses

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

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

4. Atmospheric CO2 levels have increased by about 30% since 1800 because of the clearing of forests, combustion of cutting and scrap timbers, and because of the burning of fossil fuels.

5. Yes, I do think the school bus idling policy will significantly affect annual worldwide supply of fossil fuels that are converted to carbon dioxide because as years go by, more fossil fuels will be needed  for more buses.

6. The school buss idling policy is necessary to help preserve the burning of fossil fuels. And hopefully with this policy it will help when years go by and more fossil fuels will be needed.

Unit 3 SAS (p.233) #1-30 (except: 2,4,9,14,24,25)
1) A hydrocarbon is a molecular compound that only contains atoms of hydrogen and carbon.

3) Petroleum is a nonrenewable resource and can be used as both fuel, which can be converted to gasoline, can provide heat,  can deliver energy, and can be used to make manufactured goods. 

5) By saying crude it is meant that it is unrefined.

6) ???????

7) Some fuels obtained from crude petroleum include: kerosene, petroleum oil, gasoline, and lubricating oil.

8)
a. Candles, water bottle, soap, rubbing alcohol are all houshold items made from petroleum. 
b. palm oil could replace petroleum in candles, aluminum could replace petroleum in water bottles, detergenst could replace petroleum in soap, and Isopropyl alcohol could replace petroleum in rubbing alcohol. 

10) 
a. Middle East has the most petroleum reserves.
b. Western Europe has the least petroleum reserves. 

11)
a. Central Asia, Far East, and Oceania has the most petroleum consumption.  
b. Africa has the least petroleum consumption. 

12) Density could be used to seperate two different liquids if the substance are not dissolvable.

13) A mixture with the substances water and acetone would be the easiest to seearate from each other by distillation because water has the highest boiling point, while acetone has the lowest boiling point, causing it to be easily seperated. 

15)
    
















16) Fractional distillation differs from simple distillation because fractional distillation is a refining that does not seperate each compound in a mixture, but produces several distinctive mixtures, called fractions, while simple distillation is the seperation of liquid substances according to their 

differing boiling points.

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

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