final study guide

·      Stronger attractions among atoms result in high boiling point

·      A CuO sample should weight more since the oxygen combines with the Cu and now gets weighed

·      Burning hydrocarbons such as methane releases CO2 gas and water vapor and heat energy

·      If one mole of potassium metal has a mass of 31.9 grams, 6.02 x 10²² atoms are in 3.91 grams potassium

·      Metals conducting electricity is a physical property

·      Diamond is the strongest allotrope of carbon

·      We made two types of alloy in the Alloy lab

·      The alloy in the metal brass has a different hardness than that of copper

·      In the carbon cycle, carbon is not found in the molecules of H20

·      Burning natural gas, coal, and gasoline releases CO2, which threatens the ozone layer

·      Radio waves have the lowest frequency and least energy

·      The best description of water and acetone in a distillation apparatus is:

o   The acetone boils then re-condenses into a beaker, then the water boils separately and re-condenses into a beaker

·      Destroying rainforests leads to more CO2 in the atmosphere

·      Driving cars with internal combustion gasoline engines leads to more CO2 in the atmosphere

·      Plant photosynthesis takes away CO2 from the atmosphere

·      The burning of fossil fuels release CO2 and decrease O2 in the atmosphere

·      7 electrons are in the outer shell of F    

·      OIL RIG- oxidation is lost, reduction is gained

·      Renewable source- can be replenished by natural processes

·      Nonrenewable source- cannot be replenished by natural processes

·      Doping- adding impurities to a semiconductor to enhance its electrical conductivity       

·      Cathode- an electrode in an electrochemical cell at which reduction occurs

·      Anode- an electrode in an electrochemical cell at which oxidation occurs

·      Hydrocarbons- molecules composed of only carbon and hydrogen atoms

·      The fewer carbon atoms there are, the lower the boiling point is        

·      If it ends in “gen” ,“u“ or ”ine” it is a diatomic element  (GEN-U-INE)

day 3 week 6

3 SAS: 

31. a. propane C3H8 

       b. pentane C6H12

32. "-ane" refers to the carbon bonds. 

33. Yes, the molecules are all isomers of each other because they have the same molecular formulas but different arrangement of atoms. 

34. on paper 

35. The shortest-chain alkane that can demonstrate isomerism is butane. 

36. An unbranched hydrocarbon molecule can be represented as a linear chain as well as a zig-zag chain as long as it is composed of four or more atoms. 

37. on paper 

38. a. long straight chain 

        b. a long branched chain 

        c. a short branched chain 

3 SBS: 

1. Petroleum is sometimes considered "buried sunshine" because petroleum's plant energy is found from the sun and is now buried under the ground. 

2. a. potential energy is stored energy, and an example is a spring within a toy 

     b. kinetic energy is energy related to motion, and an example is a toy moving, triggering the spring to unwind

3. In a chemical reaction, a chemical bond is broken and reactant atoms reorganize to form new bonds. 

4. A molecule of methane has more potential energy because the overall chemical change is exothermic. 

5. a. potential energy 

    b. potential energy 

    c. kinetic energy 

    d. potential energy 

    e. kinetic energy 

6. Energy is required to break chemical bonds because there is no other way to break the bonds and order reactant atoms to reorganize and from new bonds. 

7. a. exothermic 

     b. exothermic

     c. endothermic 

8. The quantity of energy stored in the bonds of the reactants compared with the quantity of energy stored in the bonds of the products is greater, thus creating an exothermic reaction. 

9. on paper

10. The law of conservation of energy states that energy can change form but cannot be created or destroyed in any chemical reaction or physical change. 

day 2 week 6

B.3 


1. Human exposure to ultraviolet radiation is potentially more harmful than exposure to infrared radiation because certain forms of radiation can lead to skin cancer and sunburn. 


2. Visible solar radiation plays a major role in the interaction of visible light with electrons in chlorophyll molecules, (photosynthesis), and it also causes red sunsets and blue skies because of the scattering of the sun's radiation. 


3. Dry, arid regions in the US experience wider air temperature fluctuations from night to day than do states with more humid conditions because as warmer air expands, it's density decreases and the warmer air is then displaced by colder, denser air, causing the warmer air to rise. Another factor could be the earth's rotation which influences wind patterns. 


4. a. The warmer the air is, the density decreases and is then replaced by colder air. 
     b. The colder the air is, the density increases and is replaced by warmer air. 


B.8 


1. 100 kg of carbon dioxide is produced daily by all 10 Riverwood High School buses. 


2. 40 liters of fuel are consumed daily by buses idling at Riverwood High School. 


3. In a 180-day school year, 18,000 kg of carbon dioxide would be released into the atmosphere by these buses while idling. 7,200 liters of duel would be consumed. 


Unit 3 SAS


1. A hydrocarbon is a molecular compound that only contains atoms of hydrogen and carbon. 


3. Petroleum is used as a fuel and is converted to gasoline. Petroleum is also used as a raw material from which many products are manufactured. 


5. Crude oil is called "crude" because it is not processed or refined in its natural state, therefore we can not commercially use it until it is transported. 


6. a. 23,843
    b. 21,220


7. Propane and gasoline are fuels obtained from crude petroleum. 


8. Clothing, CDs, sports equipment, and roller skates are items made from petroleum 
  
10. a. The Middle East has the most petroleum reserves relative to its population 
       b. Western Europe has the least petroleum reserves relative to its population 


11. a. North America and Western Europe consume a greater proportion of petroleum than they possess 
      b. The Middle East and Africa consume a smaller proportion of petroleum than they posses 


12. Separation of two different liquids will only work if the substances are insoluble in each other. 


13. Acetone and water would be easiest to separate from each other by distillation because they are insoluble. 


15. on paper 


16. Fractional distillation does not separate each compound in crude oil, and it produces several distinctive mixtures instead. 


17. Light- refined oils 
       Intermediate- gas oil
       Heavy- wax 


18. The fraction with the highest boiling point range will be at the bottom of the distillation tower. 


19. The fractional distillation process could be repeated until the components of each fraction are fully separated. 


20. Pentane, hexane, octane, and methane. 


21. A covalent bond is a bond formed by the sharing of electrons between atoms. 


22. Atoms with filled outer electron shells do not form covalent bonds because they can be bonded separately. 


23. The analogy describes the sharing of electrons both working together to hold the same atoms together in a covalent bond. 


26. a. a structural formula illustrates the complete concept of a molecule in a graphical representation, whereas the molecular formula is a less detailed representation of a molecule. 
        b. a structural formula is an inadequate representation of an actual molecule because there is not an accurate representation of where an electron's mass is located. 


27. on paper 


28. The electron-dot representation of a carbon atom shows only four dots because it only represents the valence electrons for carbon. 


29. on paper 


30. a. 108 
        b. 192 
        c. 120 
        d. 216

day 1 week 6

Unit 4 BS: 


1. The frequency of electromagnetic radiation is directly proportional to its energy. 


2. The word "spectrum" is a good descriptor of the types of energy found in electromagnetic radiation because it represents the particular types of electromagnetic radiation with each type representing a range of energy.


3. Visible light is useful in plant photosynthesis while other forms are not because visible light interacts with electrons in chlorophyll molecules, which provides the energy needed for photosynthesis. 


4. a. infrared, visible light, ultraviolet   
     b. infrared radiation is heat radiation, visible light is the only light that is visible to the human eye, ultraviolet radiation is necessary for human exposure because vitamin D is produced when the skin receives moderate doses included in sunlight


5. Ultraviolet light is effective for sterilizing protective goggles, while visible light is not, because UV-C radiation is the most energetic form and kills bacteria and destroys viruses. 


6. Infrared radiation from the sun cannot reach Earth's surface because it is absorbed by CO2 and gaseous H20 molecules in the atmosphere. Visible radiation, particularly the scattering of the sun's radiation by water, air, and dust is the cause of red sunsets and blue skies. If all the Ultraviolet radiation reaching the atmosphere actually reached the surface of the earth, the earth would be destroyed. But UV radiation exposure is necessary because of the vitamin D produced. 


7. Two main effects of the solar radiation that reaches Earth's surface are the warming of the atmosphere, oceans, and continents. Another effect is the production of the hydrologic cycle.


8. a. Lake water reflects light and absorbs heat when exposed to sunlight. Asphalt quickly warms up when exposed to sunlight. 
     b. Water in the form of vapor is a greenhouse gas and it absorbs infrared light, and asphalt reflects light directly. 


Unit 4 SBS: 


14. Atmospheric CO2 and water vapor help maintain moderate temperatures at Earth's surface by helping form carbohydrates through photosynthesis. 


15. a. natural process- photosynthesis
            human process- clearing forests
       b. natural process- methaneogenesis 
            human process- fossil fuel production 


16. a. increase- if sufficient CO2 were added, the atmosphere could retain enough additional infrared radiation from the sun to increase Earth's surface temperature. 
       b. decrease- reduce greenhouse emissions by developing energy efficient technologies and relying more heavily on renewable energy. 


17. A greenhouse with transparent glass walls is warmer than a structure with opaque wooden walls because the greenhouse effect causes the trapping and returning of infrared radiation. 


18. on paper 
CO2 gas, CaC03, CH4


19. CO2 gas, CaC03, and CH4 are chemical reservoirs of carbon atoms.


20. Over time, a particular carbon atom can be part of the atmosphere as a gas, the lithosphere as animal or plant waste, and the hydrosphere as limestone.

day 5 week 5

2SDS: 


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


8. White gold and stainless steel are examples of common alloys. 


9. Fe (iron) is a component of both steel and stainless steel. 


10. Ni3Al is a low-density, strong metallic alloy of nickel and aluminum and it is used as a component of jet aircraft engines. 


11. The location of semiconductors and metalloids are the same on the periodic table. 


12. Three elements that are commonly used for doping semiconductors are phosphorus, arsenic, aluminum, and gallium. 


13. The primary use of the products of semiconductor technology is silicon-based items. 

day 4 week 5

2SCS: 


18. a. Reusing is using an item again after it has been initially used. Recycling is processing reused materials into new products. 
      b. Reusing grocery bags, recycling water bottles 


19. a. water, oxygen, timber, sun 
       b. copper, oil, gas, coal


20. a. reusing 
        b. recycling 
        c. reusing


21. The life cycle of a light bulb and a newspaper are similar because in both processes, raw materials are obtained and then refined into the desired material. 


2SDS: 


1. An allotrope is a different form of an element that has distinctly different physical or chemical properties. 


2. Oxygen and nitrogen form allotropes. 


3. a. The properties of a diamond, a chunk of coal, and pencil lead are different because: a diamond has the highest melting point among all of the other elements and it's cost depends on it's quality and esthetic characteristics, a chunk of coal is not very expensive, and pencil lead is made of graphite. 
     b. Their properties are different because the atoms are bonded together differently
     c. The cut, appearance, and quality of these materials all effect and differentiate their costs


4. Engineered materials differ from natural materials because they are made for specific purposes and can be made up of natural materials, however, natural materials are untouched and unaltered through manmade changes.  


5. Two advantages of using engineered ceramics in high-temperature applications are that the efficiency is increased, therefore fuel use is reduced. A disadvantage is that ceramics can fracture if exposed to sudden temperature changes. 


6. Polyethylene can be tailored to display properties for specific applications. Optical fibers are also being developed to replace conventional copper. 

extra credit report #5

Why we sunburn 

• Researchers have discovered a molecular signal that triggers sunburns

• When our skin cells are exposed to UVB radiation, a specific form of RNA is damaged. The damaged RNA is then released as a signal of solar injury and triggers the healthy cells to create the production of factors that induce inflammation

• The point of the entire process is to remove the sun-damaged cells, because they  could turn cancerous if not cleared away 

• People with certain auto immune disorders are very sensitive to sun exposure, and blocking the RNA pathway could be a way to reduce inflammation in these patients. However, blocking the RNA in healthy patients just to reduce the risk of sunburn could be dangerous because this process is an important way for the body to heal and get rid of damaged cells 

• "The inflammatory response is a normal part of our protection against the sun", said Dr. Gallo, a professor of medicine at the University of San Diego 

http://www.scientificamerican.com/article.cfm?id=why-we-sunburn

day 3 week 5

2SCS: 


13. a. 6 moles are needed
      b. 5 moles are produced
      c. 5 moles are produced


14. a. 1 mole can be produced 
      b. 621 g can be produced
      c. 28 g can be produced 
      d. 415 is the mass that will produce 415 g


15. In carbon dioxide, oxygen's molar mass is 32 and carbon's molar mass is 12, therefore you would divide oxygen's molar mass by the total mass of both atoms and multiply that by 100%, and get 72%. 


16. a. 216/248 = 87% 
     b. 54/102 = 52%
     c. 40/100 = 40% 


17. a. lead is 10% of PbSO4 
       b. there is 60% PbSO4 in the ore sample
       c. Pb is 68% in the total ore sample 
       d. on paper 

day 2 week 5

2SCS: 


1. The law of conservation of matter states that matter is neither created nor destroyed in a chemical reaction. 


2. A scientific law is a law that summarizes what has been learned by careful observation of nature. 


3. "Using things up" means that materials are chemically changed, not destroyed. 


4. a. sn- 1, H-1, F- 1 ---> Sn- 1, F- 2, H- 2. This equation is not balanced 
     b. Si- 1, O- 2, C- 1 ---> Si- 1, C- 2, O- 1. This equation is not balanced 
     c. Al- 1, O- 3, H- 6, Cl- 3 ---> Al- 1, Cl- 3, H- 6, O- 3. This equation is balanced 


5. a. 3 
     b. 2
     c. 1  


6. on paper 


7.  on paper


8.  a. Na- 2, S- 1, O- 4, K- 2, Cl- 1 ---> Na- 2, Cl- 1, K- 2, S- 1, O- 4. 
      b. Yes, the equation is balanced


9.  on paper 


10. a. 32 
       b. 48
       c. 100
       d. 58
       e. 243


11. on paper 


12. on paper

reactivities of metals lab

Adam 

Sydney

Livia

Abstract 

The purpose of this lab was to observe and record the reactions of zinc, magnesium, and copper in 4 different solutions including copper nitrate, magnesium nitrate, zinc nitrate, and silver nitrate. It was difficult to keep track of which metals reacted with which solution when we were recording our observations, but everything worked out in the end and we concluded that this lab was fairly simple. After gathering all of the class data, we found that zinc and magnesium nitrate could have easily been eliminated as solutions because none of the metals reacted with them. 

Procedure

We first constructed a data table in order for us to record our upcoming observations. Once we got the strips of each metal, we began to clean the surface by rubbing it with sandpaper. Then we placed the strips in each well of the wellplate. After placing 10 drops of 0.2 M solution in each sample, we waited several minutes before recording our observations. 

Metals:	Reaction w/ Cu2 + Copper Nitrate	Reaction w/ Mg2+ Magnesium Nitrate	Reaction w/ Zn2+ Zinc Nitrate	Reaction w/ Ag+
Copper:	NR	NR	NR	Tope/Brown Bubbles formed where Ag+ made contact - foamy
Zinc:	Dark spot on the metal where Cu2+ made contact.	NR	NR	All liquid formed a large and black pool of Ag+ on top of the metal strip.
Magnesium:	Turned blue w/a lot of light blue formed on the strip. Cu2+ surrounding it turned green.  Formation of a solid.	NR	NR	Brown like precipitate formed on the bottom of the well plate. Black particles formed on the metal strip.

1. Magnesium and zinc both reacted with the same amount of solutions. 

2. Copper reacted with the fewest solutions. 

3. We would not expect silver metal to react with any solution because it is very unreactive.
4. Magnesium, zinc, copper.
5. The outside surface of a penny is made of copper instead of zinc because zinc is more chemically reactive.
6. a. If silver was less expensive, then it could be a good choice for the inside of a penny because it is extremely unreactive. 
     b. Because it's very expensive and hard to obtain. 
7. a. Silver is most likely to be found in an uncombined state in nature. 
     b. Magnesium is least likely to be found chemically uncombined with other elements.
8. a. Yes it would have been possible to eliminate one of more of the metal-solution combinations and still obtain all the info needed to create chemical activity ratings for the four metals.
      b. Magnesium nitrate and zinc nitrate could have been removed for all of the metals.

With the aggregated class data known, we could easily conclude that all of the metals did not react with zinc and magnesium nitrate. We also found that all of the metals reacted with silver and copper nitrate. 

day 5 week 4

2BSBS:


9. Active metals are more difficult to process and refine than less active metals because active metals tend to corrode more easily and are less durable.


10. We did not complete this lab.


11. Most metals exist in nature as minerals rather than pure metallic elements because the metals are found combined with other elements within more stable compounds which then can be refined to produce free metal.


12. A calcium metal with chromium (III) chloride is more likely to react together because calcium is is more reactive than chromium (III) chloride.


13. Zn2+ (aq) +  2 Ag(s) --> Zn(s) + 2 Ag+ (aq) is more likely to occur.


14. It is a poor idea to stir a solution of lead (II) nitrate with an iron spoon because lead is less reactive than iron.


15. Reduction is what chemists classify any chemical change in which a reactant can be considered to gain one or more electrons. Oxidation is when any reactant appears to lose one or more electrons. Oxidation-reduction occur together because whenever one reactant loses electrons, another reactant must gain them.


16. a. Au2+ + 2 e- --> Au
     b. V --> V2+  + 2 e-
     c. Cu2+ --> Cu + e-


17. a. Reduction reaction
       b. Oxidation reaction
       c. Reduction reaction


18. a. Zn2 + has been oxidized because it loses 2 electrons
       b. Ni has been reduced gains 2 electrons 
       c. Zn


19. a. Al + Cr3+ ---> Al3 + Cr 
       b. Mn2+ + Mg ---> Mn + Mg2+ 


20. a. Al + Cr3 --> Al3  + Cr
        b. Mn2 + Mg --> Mn + Mg2+


21. a. Electrometallurgy- using an electrical current to supply electrons to metal ions, thus reducing them. This process is used when no adequate chemical reducing agents are available or when a very high purity metal is sought
     b. Pyrometallurgy- treating metals and their ores with heat. Carbon and carbon monoxide are common reducing agents
    c. Hydrometallurgy- treating ores and other metal-containing materials with reactants in a water solution. Used to recover silver and gold from old mine tailings by a process called leaching


22. a. Magnesium- electrometallurgy
        b. Lead- pyrometallurgy

metal report: tin

Tin: Sn 

• Atomic number- 50 
• Atomic weight- 118.69
• Melting point-231.93 C 
• Boiling point- 2602 C

• The symbol for tin (sn) derives from the latin word for tin, stannum
• Archeological evidence suggests that people have been using tin for at least 5500 years
• Tin makes up only about 0.001% of the earth's crust and is chiefly mined in China
• Tin is often used as a protective coating on other metals, like a tin can, because of it's high resistance to corrosion 
• Tin alloys are used mainly as a solder for joining pipes and electrical circuits. Tin foil was also once a common wrapping material for foods, but has now been replaced by aluminum foil
• When tin is cooled below 13.2 C, it slowly changes from white to grey 
• Tin very rarely occurs free in nature 
• Organic tin bonds are dangerous to humans and can lead to tin poisoning. However, tin as single atoms are not toxic to humans or the environment 
• When a bar of tin is bent, a crackling sound known as the tin cry can be heard due to the duplication of crystals
• Cost of pure tin- $24 per 100 g 
• Cost of bulk tin- $1.80 per 100 g 

Properties of tin

Malleability and ductility	High
Electrical conductivity	Relatively low
Thermal conductivity	Relatively low
Chemical reactivity	Relatively low
Resistance to corrosion	Low in acids, high in distilled or tap water Presence of oxygen in a solution accelerates corrosion
Useful alloys formed	Pewter, solder, fusible metal
Color and luster	Silvery white, shiny

World tin mine reserves

Country	Reserves
China	1,700,000
Malaysia	1,000,000
Indonesia	800,000
Peru	710,000
Brazil	540,000
Bolivia	450,000
Russia	300,000
Thailand	170,000
Australia	150,000
Other	180,000