Farewell Blog

Farewell

Hey guys! Thanks so much for all of your views. I hope this blog helped any of you who had any chemistry questions. 

Sadly this is my last blog :( 

So what I took away from chemistry that I will remember is the studying processes and how to remember old concepts. Study techniques were key to this class and I think I learned how to manage my time better this summer. 

I hope you all have a great Sum13mer. Thanks for everything! 

Finals Study Guide

Final tomorrow! Yikes! Study time!

      *        What makes sunsets red? Answer: Light scatters in particles

·         Allotropes? Answer: Different forms of an element ex. graphite, diamond, buckmisterfluorine, soot

·         Covalent bonds (vs. ionic bonds)? Answer: Covalent bonds share electrons while ionic bonds are magnetically attracted to each other. Covalent bonds are stronger. 

·         Carbon has four covalent bonds:  draw them for CH₄  or C₂H_{6 Answer: (see paper)}

·         Which are the lowest energy electromagnetic rays? Answer: Infrared (heat)

·         Photosynthesis is the opposite of respiration. What are the products of each? Answer: Respiration releases CO2, but Photosynthesis takes in CO2

·         What is the atmosphere made of? Answer: Nitrogen 78%, Oxygen 20 something, Argon, Neon. Clouds and other particles.

·         What is 1 atmosphere of pressure at sea level? Answer: At sea level it is called 1 atmosphere less than 1 in the mountains. There is more air pressure at sea level. 

·         Define isomers. Answer: same molecular formula, but different structrue.

·         Explain separating compounds through Distillation by different boiling points: Answer: elements/compounds all have different boiling points. 

·         What is in rainwater that makes it acidic? Answer: CO₂

·         Define CFC’s and what they do to promote global warming. Answer: CFCs are from old air conditioners and fridges. They promote global warming because they destroy the ozone layer. 

·         How does carbon dioxide affect global warming? Answer: because of CO2 the planet's temperature could rise.

·         Hydrocarbon boiling points increase as the number of carbon atoms increase. Why? Answer:  

·         What produces CO2 and what uses it? Answer: Photosynthesis uses CO2 and respiration produces it. 

·         What is carbon monoxide (CO) and how is it produced? Answer: CO is a harmful compound and it is produced when the reaction of burning methane does not have enough oxygen to fully combust so it makes carbon monoxide. 

·         Define a catalyst. Is it used up in a reaction? Answer: Speeds up a reaction.

·         Define fractional distillation and what it’s used for. Answer: Used for refining oil. 

·         How much garbage does the average person create per day? Answer: 4-7 pounds

·         What byproducts come from manufacturing processes? Answer: use up resources, cause some pollution, pure zinc goes to zinc oxide so it is less useful for example. 

·         Kinetic vs. potential vs. chemical energy Answer: Kinetic is motion, potential has the potential to move, and chemical has the potential to move (in a chemical way) 

·         Why doesn’t an upside down jar lower into water easily? (air) Answer: Air has actually volume so it cannot squish down. 

·         What does it mean to “use up” chemicals? Answer:  

·         Altitude is related to pressure. High altitude = less pressure

·         Molarity is solution concentration

·         Kjoules measure energy

·         When we extract a metal from an ore, are we oxidizing or reducing it? Answer: reducing as we purify it. 

Things for me to go over before the final

1. The carbon cycle: We inhale O2 and release CO2.
Examples: plants use CO2 and solar energy to form carbohydrates through photosynthesis
- Moves in the oceans
- trapped in fossil fuels

2. Photosynthesis: CO2 is needed for this process, so it decreases CO2 from the atmosphere.
- Plants use CO2 and solar energy form carbohydrates through this process.
- Visible light is the electromagnetic waves that provide energy for plant photosynthesis.

Feedback on the summer Chemistry course

1. What has worked well this summer?

- I think that working together in our lab groups has been very rewarding because we learned to work together as a group and assign jobs to each person.

2. What suggestions do you have for tweaking or changing the course?

- Working together on the practice quizzes before we take our mini quizzes. We did that today and it helped a lot.

3. How can we go even further with presentations about individual interests a la Economist reports? Can we make some of them group presentations, even more creative, mini-research projects, or even videos or performances or experiments?

- I like the economist presentations how they are now, but maybe we can try to know our project well enough not to look at the board. I like the idea of videos or maybe powerpoints for the reports too!

4. How can we use blogs more efficiently?

- I think we use the blogs very well now.

5. Should the instructor check all homework on the blogs?

- Yes so he can see that we actually finished our homework.

6. With a new head of school who is calling for more creativity, even in science, what whacky vision do you have for learning Chemistry that has more joy, less fear of G.P.A and more excitement about learning about science?

- More projects that help us appreciate science. Maybe looking for the science behind things that we didn't know had science in it like in music or dancing. 

Finals Review

1. What gas predominates in the atmosphere?

- Nitrogen

2. What other molecules and gasses are in the atmosphere?
- CO2, O2, CH4, Ne, Ar, H, H2O.

3. Which cause the greenhouse effect? Draw it.















4. How is energy transmitted from the sun to the Earth?
- UV rays and visible light.

5. Which of the sun rays has the lowest energy?
- Infrared

6. CFCs are released into the atmosphere by discarding old _______. What is the danger of CFCs?
- Airconditioners and refrigerators. They destroy the ozone layer. 

7. Why are cows a menace?
- They produce methane.

8. Define covalent bond.
- The sharing of electrons.

9. Define valence electrons.
- the electrons on the outer shell. 

10. Define hydrocarbon. Name and draw two hydrocarbon molecules.
- Hydrocarbon is atoms that only have carbon and hydrogen. CH4 (methane) C8H18 (octane) are examples. 

11. When you burn propane, what gases are released? What else is released? Why?
- Heat is released, H2O is released, CO2 is released because it is an exothermic reaction. 

12. Write out the equation for the burning of methane, including the release of 890 kj (kilojoules) or energy. 
- CH4 + O2 --> H2O + CO2 

Final Review Points: 

• What makes sunsets red? -Light scatters in particles. 
• Allotropes: Graphite, Buckmisterfluroine, soot, diamond
• Carbon has four covalent bonds
• Which are the lowest energy electromagnetic rays? Infrared (heat)
• Photosynthesis is the opposite of respiration. What are the products of each? Respiration: CO2, Photosynthesis: Oxygen
• What is the atmosphere made of? Neon, Argon, Hydrogen and Nitrogen
• Define isomers: different structure, same formula (molecular structures)

Quiz Questions I need to go over

1. Which contains the lowest proportion of electromagnetic waves in solar energy?
- 9% UV

2. CFCs affect global warming in what way?
- CFCs don't have any effect on the temperature of the planet and escaped CFCs destroy the ozone layer which protects our planet from the sun's UV rays.

3. Unlike electromagnetic waves, sound waves can travel through a vacuum.
- False

4. Plant photosynthesis
- takes away CO2 from the atmosphere

5. Destroying rainforest
- leads to more CO2 in the atmosphere

6. Driving cars with internal combustion gasoline engines
- leads to more CO2 in the atmosphere

7. Plant photosynthesis depends on which source for its energy?
- Visible light from the sun

8. Every day we create how much garbage?
- 4 to 7 pounds per day.

9. In the Carbon Cycle, which steps do NOT happen?
- Burning fossil fuels releases O2 and decreases CO2 in the atmosphere.

10. How many types of alloy did you make in the Alloy lab?
- Two

11. Can sound travel through a vacuum?
- No, only electromagnetic waves can

12. The alloy in the metal brass has a different hardness than that of copper?
- True.

Blog about fossil fuels vs. alternative energy and vehicles. How do hybrid vehicles help the planet? Electric vehicles? Do some research.

Hybrid vehicles help the planet because they use a rechargeable energy storage system to supplement fossil fuel energy for vehicle propulsion. Hybrid engines are more efficient and smaller than traditional fuel engines. While traveling, other hybrid vehicles use regenerative braking to generate electricity. 

Electric cars on the other hand do not help the planet. In fact, they are environmental destroyers. When the electricity that feeds them comes not from gas-fired and coal-fired power plants (global warming bandits), electric cars are especially not environmentally friendly. They are also toxic. 

where electric cars obtain their electricity

hybrid car parts

Study Guide

Valence Electrons
- on the outer shells; so loose they form other bonds; denoting electrons involved in or available for a chemical bond formation

Valence electrons in carbon
- 4

Mg
- 2

Na
- 1

Covalent bond
- share electrons

C-14 #neutrons
- 8

What in the atmosphere reflect solar energy?
- clouds, water vapor and particles

Uv helpful?
- yes for sterilizing and provides vitamin d.

Source of all energy?
- sun

CO
- carbon monoxide

Structural isomers
- when molecular formulas are the same, but their structure is different.

Fe 58
- isotope; 49 neutrons

Cl outer shell electrons?
- 7

Argon's outer shell?
- 18

Which uv causes cancer?
- UV-B

C bonds with how many H?
- 4 (methane)

highest frequency waves? lowest
- highest: gamma rays
- lowest: radio waves

waves for photosynthesis
- electromagnetic waves

rate of ocillation
- frequency

large hydrocarbons have high boiling points why?
- intermolecular forces

potential, kinetic, chemical, mechanical
- potential: possibility to move
- kinetic: can move
- chemical: potential energy but in chemical bonds
- mechanical: motion

Homework Due Wednesday July 24

#31-38 pg. 235

31. A. Formula: C3H8

            Molar Mass: 44 g
       B. Formula: C5H12
             Molar Mass: 72 g

32. Each name is composed of a prefix, followed by -ane (designating an alkane). The prefix indicates the number of carbon atoms in the backbone carbon chain. The prefixes are derived from Greek, hex meaning six. 

33. No because they do not have identical molecular formulas. 

34. 

35. Butane.

36. Saturated hydrocarbons are linear, but they are arranged as zig-zags for models and diagrams. 

37. A. 

            

    B. The branched chain molecule.

38. A. Short

       B. Long

       C. Short 

#1-10 pg. 258

1. The energy released by burning fuels represent energy originally captured from sunlight by prehistoric green plants during photosynthesis. Thus, fossil fuels such as petroleum can be thought of as forms of buried sunshine.

2. A. Potential energy is energy of position (or condition). An example is a wind-up toy race car. The "winding-up" energy that was originally supplied tightened a spring in the toy.

    B. Kinetic energy is energy related to motion. An example is when the toy car moves, the spring unwinds, providing energy to the moving parts.

3. When an energy-releasing chemical reaction takes place (such as when fuel burns), bonds break and reactant atoms reorganize to form new bonds.

4. Butane because it contains more carbons so the molecule contains more electrons causing more potential energy.

5. A. Potential Energy

     B. Potential Energy

     C. Kinetic Energy

     D. Potential Energy

     E. Kinetic energy

6. It yields products with different and more stable bonding arrangements of their atoms.

7. A. Exothermic because energy is being released

    B. Endothermic because it is breaking apart

    C. Exothermic because energy is being released

8. Burning a candle is exothermic because it is an energy-releasing process because and energy is being given off. 

9. 

10. No energy is created nor destroyed. 

Blog about distillation to separate alcohol and water

Homework Due July 23

pg. 344 #1-4

1. Human exposure to ultraviolet radiation is more harmful than exposure to infrared radiation because ultraviolet can cause harsh sunburns and skin cancer. 

2. Visible radiation can cause red sunsets and blue skies; visible radiation can provide energy needed for photosynthesis. 

3. When solar energy strikes Earth, clouds reflect about 30% back into space and 70% moves through the atmosphere to reach Earth's surface. Energy that reaches the surface can be reflected or absorbed. Objects that absorb the Sun's UV and visible light reradiate it at lower-energy wavelengths such as infrared radiation, which is absorbed by atmospheric gases such as water, CO2, and methane. Infrared radiation can be absorbed and reradiated by atmospheric gases and Earth's surface several times before escaping into space. This "greenhouse effect" helps maintain warm temperatures on Earth. 

4. A. Daytime temperatures would be colder. 
     B. Nighttime temperatures would freezing colder without the presence of the sun.

pg. 350 #1-6

1. 0.25 kg of carbon dioxide

2. 0.10 liters of fuel 

3. 2,592,000, carbon; 64,800, fuel

pg. 233 #1-30 (except 2, 4, 9, 14, 24, 25)

1. A hydrocarbon is a compound of hydrogen and carbon, such as any of those that are the chief components of petroleum and natural gas.  

3. Petroleum is mostly used as a fuel in which it is converted to gasoline that powers millions of U.S automobiles, each traveling an average of 14,000 miles annually. Other petroleum based fuels provide heat to homes and to office buildings, deliver energy to generate electricity, and power diesel engines and jet aircraft. 

5. Oil is crude because it can be pumped from underground in which it varies from colorless to greenish-brown to black, and can be as fluid as water or as resistant to flow as soft tar. 

6. A. 150
     B. 29,081

7. Pipeline, ocean tanker, train, or barge to oil refineries. 

8. CDs, sports equipment, and clothing. 

10. A. United States
      B. Middle East

11. North America, Central and South America, Western Europe, Central Asia, Far East, and Oceania. 

12. Liquids that each have different densities that cannot mix form two separate layers, with denser liquid forming a layer below the less dense one. The layers, using a "separating funnel", can separate the layers.

13. Cyclohexane and Acetone because they have the lowest boiling points
15. 

16. Simple distillation is the separation of a liquid and a solid by evaporation of the liquid and collecting it after it passes through a condenser to be changed into a liquid state, while fractional distillation is the more complex way to separate a substance. It is the separation of a liquid mixture. 

17. Light: oils, kerosene, and gasoline
      Middle: gas oils, fuel oils, and petrochemicals, 
      Heavy: grease, oil, and wax

18. The bottom since it's warmer at the bottom of the tower. 

19. Continue distillation, the separation or partial separation in the components. 

20. Methane, pentane, hexane, and octane.

21. The sharing of two or more valence electrons between two atoms. 

22. If the outer shell of the atom is already filled with its electrons then that means it does not need to form a covalent bond because it is already full.

23. The dogs share the same sock like the electrons share the same electrons.

26. A. Information of a structural formula has the shape of the molecules (or the molecules structure) while the molecular formula does not.
       B. It provides the structure, or physical description of the molecule. 

27. A. 
        B.

28. The dots only represent the valence electrons.

29. A. C9H20
       B. C16H34
       C. C10H22
       D. C18H38

30. A. 128 g
       B. 226 g
       C. 142 g
       D. 254 g

Final Study Guide #1

1. Which gas predominates in the atmosphere?
- Nitrogen

2. What other molecules and gasses are in the atmosphere?
- H2O, CO2, CH4, N2O, O3, Cl3F

3. Which cause the greenhouse effect?
- When light is trapped in from the sun and attracts heat.

4. How is energy transmitted from the sun to the Earth?
- Electromagnetic radiation (spectrum)

5. Which of the sun rays has the lowest energy?
- Infrared radiation

6. CFCs are released into the atmosphere by discarding old ___________. What is the danger of CFCs?
- Refrigerators and air conditioners; CFCs degrade ozone layer.

7. Why are cows a menace?
- Releases methane which can be a greenhouse gas.

Electromagnetic Spectrum Blog

Homework Due July 22

#1-8, #14-20

1. The frequency is directly proportional to its energy; high-frequency radiation is also high-energy radiation.

2. It is useful to identify particular types of electromagnetic radiation, with each type representing a particular energy range, that together make up the electromagnetic spectrum.

3. Visible light contains chlorophyll molecules that provide energy needed photosynthesis reactions.

4. A. X-rays, ultraviolet, and microwaves
    B. X-rays are used in hospitals to tell if someone has a broken bone; u-v radiation can cause sunburn and skin-cancer; microwaves are used in everyday life to heat up frozen food.

5. UV radiation is useful to sterilize materials because it can kill bacteria and destroy viruses while visible light can only provide energy.

6. Infrared energy is retained by the atmosphere because it is heat radiation from the Sun that cannot reach Earth's surface due to being absorbed by carbon dioxide and gaseous water molecules in the atmosphere; on a clear day, more than 90% of the visible region of solar radiation directed toward earth travels down to Earth's surface. The scattering of this portion of the Sun's radiation by water, air, and dust is the cause of red sunsets and blues so visible radiation can energize electrons in some chemical bonds; UV radiation reaching the atmosphere actually reached the Earth's surface, it is likely that most life on Earth would be destroyed.

7. Certain types of molecules in the air do not absorb the Sun's VU and visible radiation, allowing it to reach the surface of Earth, but absorb any infrared radiation that is reradiated from Earth's surface, thus holding warmth in the atmosphere; earth's surface reradiates most absorbed solar radiation, but usually at longer wavelengths.

8. Asphalt absorbs almost all solar radiation that strikes it, which causes asphalt roads to become hot and radiate heat. Lake water can act like a greenhouse gas and it absorbs infrared light.

14. CO2 and water are both greenhouse gases, which means they can absorb infrared radiation and pass energy, keeping a lot of energy from being lost in the space.

15. A. Photosynthesis, Respiration; Burning coal, burning gasoline
      B. Infrared radiation, greenhouse effect; livestock, fossil fuel

16. A. Greenhouse gas would increase temperature
      B. Greenhouse gas would decrease temperature

17. Solar radiation causes the house to be warmer since the glass exposes the house to the outdoors.

18. A. 
      B. 

19. Coal, natural gas, gasoline

20. Carbon atoms become apart of the atmosphere through diffusion; carbon atoms become apart of the biosphere through photosynthesis; carbon atoms become apart of the lithosphere through burial; carbon atoms become apart of the hydrosphere through weathering.

Blog about the uses of alloys and how their properties change.

An alloy is a solid combination of atoms of two or more metals. When two elements form an alloy, their physical properties change. For example, a silvery color is formed of the alloy from copper and zinc, but they are both not silver. The alloy changes the elements' physical properties.

Homework Due Friday July 19th

7. An alloy is a solid combination of atoms of two or more metals. 

8. White gold and stainless steel 

9. Iron and Carbon

10. Red brass
      Formula: Cu + Zn
      Use: Brass is used in plumbing and lighting fixtures, rivets, ships, and screws.
      Property: Vary within the proportion of copper and zinc used and with the addition of small amounts of other elements. 

11. The metalloid silicon belongs in a class of materials called semi-conductors. Metals are good conductors of electricity whereas nonmetals are not. Semiconductors, on the periodic table, lie in between the two groups (metals and nonmetals). Some include Germanium and Silicon.

12. Phosphorus, Aluminum and Arsenic

13. A balanced amount of electricity.

Explain the difference between allotropes (O2 vs. O3).

O2 is a diatomic molecule that is found in the atmosphere. O3 is also found in the atmosphere; however, it can also act as a gas and helps protect the earth from the sun. 

Homework Due July 18

1. Allotropes are each of two or more different physical forms in which an element can exist. 

2. Tin and oxygen.

3. A. The first sample is a black solid that feels soft and bit "greasy" to the touch and leaves black marks when you rub it on paper. The second sample is colorless and glasslike (solid). It leaves deep scratch makes when rubbed on a table. The third sample is a fine, powdery solid that is made up of the roundest-shaped molecules. It's been found in prehistoric layers of Earth's crust.
    B. The first substance is a useful lubricant and a fairly good conductor of electricity. The second sample is useful as an abrasive and as a coating for saw blades. It's also an electrical insulator, which means that it does not conduct electricity. The third sample was only discovered in 1985.
    C. The first sample in one gram sells for less than a penny. The second sample, depending on its quality, can cost $50 per gram or more more than $20,000 per gram. The third sample, currently, costs between $170 and $3000 per gram, depending on the chemical supplier and the amount purchased at one time.

4. Natural materials are mined from the ground and nothing is changed from it, but engineered materials are physically altered. 

5. Advantages are hardness and rigidness, but disadvantages are resistances to wear and low chemical reactivity. 

6. Polyethylene can be tailored to display relatively soft and pliable properties or crafted to be hard and brittle, almost glasslike in its behavior. 

Explain the relationship between atoms, neutrons, protons, electrons, and molecules. Give examples using CO2 and H2O

Protons, neutrons and electrons are all inside an atom's nucleus (with electrons orbiting around it and neutrons and protons in the center). In each element (C, O, H etc.) there is a specific number of protons and electrons (must be equal) and neutrons (taking the range of the atomic number and the atomic weight). 1 C, 2 O, 2 H, and 1 O (in CO2 and H2O). 

Homework Due Wednesday July 17, 2013

Homework #13-21 pg. 181-182

13. A. 6 moles
      B. 5 moles
      C. 5 moles

14. A. 17 gm x 2 = 34 gm; 2 moles in Atom, but one mole of N2 molecules. 
      B. 621 gm 
      C. 17 gm
      D. 431 gm

15. It is a little over 27% not 67%. The way to find this is to do percent composition.

16.  A. 86.9% Ag; 9.2% S
       B. 45% Al; 47% O
       C. 40% Ca; 12% C; 48% O

17. A. 68.3%
      B. 606% (?)
      C. 59%
      D. see diagram 

18. To reuse means to use again or more than once while recycling means to convert into reusable material. 

19. Renewable: Fresh water and air, fertile soil, plants, and animals. 
Nonrenewable: Metals, natural gas, coal, and petroleum. 

20. A. Reusing
       B. Recycling
       C. Reusing

21. Newspaper becomes waste after it fulfills it's initial purpose, even though it can last longer than a lightbulb. The biggest waste is paper.