Friday, July 26, 2013
Farewell
Summer Chemistry has gone by really fast, and I have learned a lot. Dr. Forman, you are great teacher with a great personality and heart, and I hope to have you in the future. I can't believe how fast this class went, and I hope everyone a great summer.
Thursday, July 25, 2013
Feedback on the summer Chemistry course
1. I feel that Dr. Forman taught us really well because he created a stress free environment, let us socially interact, and taught us all of the concepts very thoroughly. His wonderful sense of humor also kept this 4 hour class moving in a productive manner.
2. The suggestions that I have is reducing the homework a little the last week, and taking the practice quizzes before we take the mini quiz.
3. For the economist report, we can make PowerPoint presentations, act something out in front of the class, and maybe make a video for a two week report. We can even report on a subject that we think is interesting and not from the economist every other week.
4. We could use blogs more effectively by posting something that's unique about chemistry that we find interesting on our blogs.
5. I don't the instructor should check all the homework on the blogs because we have a substantial amount of homework daily, so it would take a long time to check everyone's homework. I think the instructor should just look to see if it is completed.
6. I really like the vision that the new head of school has because the students at our school right now are always stressed about their GPA, which is great that they care about their grades, but I don't feel that it is healthy for teenagers to be feeling that pressure. I hope that we have more labs in science, fun teachers like Dr. Forman to make science less stressful and more enjoyable, more creativity in science, like the little drawings on our quizzes that we drew, and to interact with our friends and learn from each other.
2. The suggestions that I have is reducing the homework a little the last week, and taking the practice quizzes before we take the mini quiz.
3. For the economist report, we can make PowerPoint presentations, act something out in front of the class, and maybe make a video for a two week report. We can even report on a subject that we think is interesting and not from the economist every other week.
4. We could use blogs more effectively by posting something that's unique about chemistry that we find interesting on our blogs.
5. I don't the instructor should check all the homework on the blogs because we have a substantial amount of homework daily, so it would take a long time to check everyone's homework. I think the instructor should just look to see if it is completed.
6. I really like the vision that the new head of school has because the students at our school right now are always stressed about their GPA, which is great that they care about their grades, but I don't feel that it is healthy for teenagers to be feeling that pressure. I hope that we have more labs in science, fun teachers like Dr. Forman to make science less stressful and more enjoyable, more creativity in science, like the little drawings on our quizzes that we drew, and to interact with our friends and learn from each other.
Wednesday, July 24, 2013
3SBS 11,12 p. 258
11. a. ii
b. iii
c. ii
d. i
12. The remaining 75% of gasoline's chemical energy is lost to the surroundings as heat (thermal energy).
3SCS 1, 3, 6, 13 p.279
1. a. 1
b. 2
c. 3
d. large molecules composed of 500 to 20,000 or more repeating units.
3. synthetic polymers: paint components, fabrics, rubber, insulating materials
natural polymers: silk, wool, DNA, cellulose and proteins.
6. Unsaturated is used to describe the structures of alkenes and alkynes because alkenes, which contain carbon double bonds, are described as unsaturated hydrocarbons. Because of their double bonds, alkenes are more chemically reactive, and therefore better builder molecules than are alkanes.
13.
b. 2
c. 3
d. large molecules composed of 500 to 20,000 or more repeating units.
3. synthetic polymers: paint components, fabrics, rubber, insulating materials
natural polymers: silk, wool, DNA, cellulose and proteins.
6. Unsaturated is used to describe the structures of alkenes and alkynes because alkenes, which contain carbon double bonds, are described as unsaturated hydrocarbons. Because of their double bonds, alkenes are more chemically reactive, and therefore better builder molecules than are alkanes.
13.
Tuesday, July 23, 2013
3 SBS 1-10 p.258
1. Petroleum is sometimes considered "buried sunshine" because the energy released by burning these fuels represents energy originally captured from sunlight by prehistoric green plants during photosynthesis.
2. a. potential energy: energy of position (wind-up toy race car)
b. kinetic energy: energy related to motion (movement of car)
3. When an energy-releasing chemical reaction takes place, bonds break and reactant atoms reorganize to form new bonds.
4. A molecule of butane has more potential energy.
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 in an endothermic change, energy must be added to "pull apart" the atoms in each molecule. Thus energy appears as a reactant.
7. a. exothermic: energy is released
b. endothermic: energy is added to pull apart the atoms
c. exothermic: energy is released
8. Burning a candle is an exothermic reaction because the quantity of energy stored in the reactants is less than the quantity of energy stored in the products; more energy is given off than added.
9.
10. The law of conservation of energy states that energy can change from but cannot be created or destroyed in any chemical reaction or physical change.
3SAS 31-38 p.235
31. a. C3H8
b. C5H12
32. -ane designates an alkane.
33. Yes because they have identical molecular formulas but different arrangements of atoms.
34.
35. Butane is the shortest-chain alkane that can demonstrate isomerism.
36. Because straight-chain alkanes, where each carbon atom is only linked to one or two other carbon atoms, and in branched-chain alkanes, one carbon atom can be linked to three or four other carbon atoms.
37.
b. C5H12
32. -ane designates an alkane.
33. Yes because they have identical molecular formulas but different arrangements of atoms.
34.
35. Butane is the shortest-chain alkane that can demonstrate isomerism.
36. Because straight-chain alkanes, where each carbon atom is only linked to one or two other carbon atoms, and in branched-chain alkanes, one carbon atom can be linked to three or four other carbon atoms.
37.
38. a. short chain because there is less surface area for inter molecular forces.
b. short chain because there is less surface area for inter molecular forces.
c. short chain because there is less surface area for inter molecular forces.
Monday, July 22, 2013
SAS 1-30 p. 233 except 2,4,9,14,24,25
1. A hydrocarbon is a molecule composed only of carbon and hydrogen atoms.
3. Petroleum is a valuable resource because burning it provides nearly half of the total annual U.S. energy needs, and it is separated into simpler mixtures.
5. Crude oil 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. 11%
b. 89%
7. Several fuels obtained from crude petroleum: gasoline, other petroleum-based fuels provide heat to homes and to office buildings, deliver energy to generate electricity, and power diesel engines and jet aircraft.
8. a. CDs, sports equipment, clothing, automobile parts, plastic charge cards.
b. wool, glass, wood
10. a. 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. Central Asia, Far East, and Oceania
b. Western Europe
12. Density would be used to separate two liquids when the substances are insoluble in each other.
13. Acetone and water would be the easiest to separate through distillation because acetone has the lowest boiling point on the chart and water the highest.
15.
17. light: aviation and motor gasoline, naphthas and solvents, kerosene
intermediate: gas oil, petrochemicals, heavy furnace oil
heavy: lubricating oil and grease, heavy oils and wax, cracking stock
18. I would expect the the fraction with the highest boiling point range to be removed at the bottom of the distillation tower because it is closer to the furnace and heavy distillates and residues, are at the bottom of the tower.
19. A way to further separate the components of each fraction would be to do normal distillation.
20. 1. Methane 2. Pentane 3. Hexane 4. Octane The higher the boiling point, the more atoms are in the molecular formula.
21. A covalent bond is the sharing of two or more valence electrons between two atoms.
22. Atoms with filled outer electron shells do not form covalent bonds because valence electrons are electrons within an atom's unfilled, outer shell, so the atoms cannot bond anymore.
23. Shared electrons hold together covalent bonds because electrons are needed to fill the first shell, and both atoms achieve the stability associated with completely filled electrons shells.
26. a. A structural formula is a chemical formula showing the arrangement of atoms and covalent bonds in a molecule, in which each electron pair in covalent bond is represented by a line between the symbols of two atoms.
b. It represents that of an actual molecule because it shows the arrangement of atoms and covalent bonds in a molecule
27.
a.
b.
28. The electron-dot reprsentaion of a carbon atom shows only four dots because it shows the valence electrons
29. a. C9H20
b. C16H36
c. C10H22
d. C18H38
30. a. 128g
b. 228g
c. 142g
d. 254g
3. Petroleum is a valuable resource because burning it provides nearly half of the total annual U.S. energy needs, and it is separated into simpler mixtures.
5. Crude oil 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. 11%
b. 89%
7. Several fuels obtained from crude petroleum: gasoline, other petroleum-based fuels provide heat to homes and to office buildings, deliver energy to generate electricity, and power diesel engines and jet aircraft.
8. a. CDs, sports equipment, clothing, automobile parts, plastic charge cards.
b. wool, glass, wood
10. a. 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. Central Asia, Far East, and Oceania
b. Western Europe
12. Density would be used to separate two liquids when the substances are insoluble in each other.
13. Acetone and water would be the easiest to separate through distillation because acetone has the lowest boiling point on the chart and water the highest.
15.
16. Fractional distillation is a process of separating a mixture into its components by boiling and condensing the components. Distillation is a process that separates liquid substances based on differences in their boiling points.
17. light: aviation and motor gasoline, naphthas and solvents, kerosene
intermediate: gas oil, petrochemicals, heavy furnace oil
heavy: lubricating oil and grease, heavy oils and wax, cracking stock
18. I would expect the the fraction with the highest boiling point range to be removed at the bottom of the distillation tower because it is closer to the furnace and heavy distillates and residues, are at the bottom of the tower.
19. A way to further separate the components of each fraction would be to do normal distillation.
20. 1. Methane 2. Pentane 3. Hexane 4. Octane The higher the boiling point, the more atoms are in the molecular formula.
21. A covalent bond is the sharing of two or more valence electrons between two atoms.
22. Atoms with filled outer electron shells do not form covalent bonds because valence electrons are electrons within an atom's unfilled, outer shell, so the atoms cannot bond anymore.
23. Shared electrons hold together covalent bonds because electrons are needed to fill the first shell, and both atoms achieve the stability associated with completely filled electrons shells.
26. a. A structural formula is a chemical formula showing the arrangement of atoms and covalent bonds in a molecule, in which each electron pair in covalent bond is represented by a line between the symbols of two atoms.
b. It represents that of an actual molecule because it shows the arrangement of atoms and covalent bonds in a molecule
27.
a.
b.
28. The electron-dot reprsentaion of a carbon atom shows only four dots because it shows the valence electrons
29. a. C9H20
b. C16H36
c. C10H22
d. C18H38
30. a. 128g
b. 228g
c. 142g
d. 254g
B.8 1-6 p. 350
1. 10 kg
2. 4 liters
3. 1800 kg
4. Atmospheric CO2 has increased have increased by 30% since 1800 because of the high amount of CO2 that is being released into the air. Riverwood buses release 10 kg of carbon dioxide daily.
5. I think it will have a worldwide because Riverwood's buses aren't the only buses that are releasing a high amount of carbon dioxide daily. School buses highly contribute to CO2 pollution.
6. I think that they think it's necessary because the head of the bus company told them they had to, so the principals don't think of the environment, they just are following the directions of the people who are in charge of the buses.
2. 4 liters
3. 1800 kg
4. Atmospheric CO2 has increased have increased by 30% since 1800 because of the high amount of CO2 that is being released into the air. Riverwood buses release 10 kg of carbon dioxide daily.
5. I think it will have a worldwide because Riverwood's buses aren't the only buses that are releasing a high amount of carbon dioxide daily. School buses highly contribute to CO2 pollution.
6. I think that they think it's necessary because the head of the bus company told them they had to, so the principals don't think of the environment, they just are following the directions of the people who are in charge of the buses.
B.3 1-4 p.344
1. Human exposure to ultraviolet radiation is potentially more harmful than exposure to infrared radiation because it can cause a sunburn, and with long term exposure is linked to skin cancer. If all the UV radiation reaching the atmosphere actually reached the Earth's surface, it is likely that most life on Earth would be destroyed.
2. Two essential roles played by visible solar radiation can warm up the Earth and powers the hydrologic cycle.
3. They experience wider air temperature fluctuations because there are less water molecules in the atmosphere. Also the sand and lighter surfaces reflect the light.
4. a. The average daytime temperature would be way hotter because more UV rays would hit the surface of the Earth.
b. The average nighttime temperature would be cooler because more heat would escape.
2. Two essential roles played by visible solar radiation can warm up the Earth and powers the hydrologic cycle.
3. They experience wider air temperature fluctuations because there are less water molecules in the atmosphere. Also the sand and lighter surfaces reflect the light.
4. a. The average daytime temperature would be way hotter because more UV rays would hit the surface of the Earth.
b. The average nighttime temperature would be cooler because more heat would escape.
Sunday, July 21, 2013
14-20 p. 361
14. Atmospheric CO2 and water vapor help maintain moderate temperatures at Earth's surface because of the hydrologic cycle and the carbon cycle maintain stable concentrations of water and carbon dioxide in their respective reservoirs, including the atmosphere.
15. a. respiration, fossil fuels, decay, combustion
b. decomposition product of plant and animal wastes, refining fossil fuels, raising livestock
16. a. The runaway greenhouse effect: as a greenhouse gas, increased water vapor may cause an even greater increase in global temperatures due to adsorption and the real ease of infrared radiation, which cause another upward spiral.
b. clouds
17. This is because more CO2 is added than can be removed by natural process.
18. a.
b. clouds
17. This is because more CO2 is added than can be removed by natural process.
18. a.
b.
1-8 p.360
1. Electromagnetic radiation consists of a broad range of energetic emissions. Particular types of electromagnetic radiation, represents a particular energy level that make up the electromagnetic spectrum.
2. Spectrum is a good descriptor of the types of energy found in electromagnetic radiation because spectrum means" any of various continua that resemble a color spectrum in consisting of an ordered arrangement by a particular characteristic (as frequency or energy)" Merriam Webster.
3. Visible light is useful in plant photosynthesis, while other forms of electromagnetic radiation are not because visible radiation can energize electrons in some chemical bonds. Visible light interacts with electrons in chlorophyll molecules, which provide the energy needed for photosynthesis reactions.
4. a. Types of electromagnetic radiation: infrared, ultra-violet, visible
b. infrared radiation: causes certain bonded atoms to vibrate more energetically.
ultraviolet radiation: can cause a sunburn, and witch ling-term exposure is linked to skin cancer.
visible radiation: can energize electrons in some chemical bonds.
5. Ultraviolet light is often used to sterilize chemistry laboratory goggles because it can kill bacteria and destroy viruses, while visible light can energize electrons in some chemical bonds.
6. Infrared radiation is absorbed by CO2 H2O molecules in the atmosphere.
Visible Radiation is scattered by water, air, and dust.
Ultraviolet radiation is absorbed in the stratospheric ozone layer.
7. Solar radiation determines climates and weather, and powers the hydrologic cycle.
8. Lake water reflects more solar radiation than asphalt because it is a lighter color, and the asphalt reflects almost not solar radiation.
2. Spectrum is a good descriptor of the types of energy found in electromagnetic radiation because spectrum means" any of various continua that resemble a color spectrum in consisting of an ordered arrangement by a particular characteristic (as frequency or energy)" Merriam Webster.
3. Visible light is useful in plant photosynthesis, while other forms of electromagnetic radiation are not because visible radiation can energize electrons in some chemical bonds. Visible light interacts with electrons in chlorophyll molecules, which provide the energy needed for photosynthesis reactions.
4. a. Types of electromagnetic radiation: infrared, ultra-violet, visible
b. infrared radiation: causes certain bonded atoms to vibrate more energetically.
ultraviolet radiation: can cause a sunburn, and witch ling-term exposure is linked to skin cancer.
visible radiation: can energize electrons in some chemical bonds.
5. Ultraviolet light is often used to sterilize chemistry laboratory goggles because it can kill bacteria and destroy viruses, while visible light can energize electrons in some chemical bonds.
6. Infrared radiation is absorbed by CO2 H2O molecules in the atmosphere.
Visible Radiation is scattered by water, air, and dust.
Ultraviolet radiation is absorbed in the stratospheric ozone layer.
7. Solar radiation determines climates and weather, and powers the hydrologic cycle.
8. Lake water reflects more solar radiation than asphalt because it is a lighter color, and the asphalt reflects almost not solar radiation.
Friday, July 19, 2013
Retrieving Copper
 |
| CuO and HCl |
 |
Cu in the filter paper  |
1. a. Lots of copper (Cu) fell to the bottom beaker instead of staying in the mixture.
b. Raise the temperature of the mixture so that more copper would dissolve in the mixture.
2. a. The amount of copper that reacted was .7 grams of Cu
b. The percent that reacted was 30%
3. a. Cu2++Zn à
Cu+ Zn2+
b.
- Zinc
- Copper
- Copper
- Zinc'
b.
Thursday, July 18, 2013
7-13 p.204
7. An alloy is a sold combination of atoms of two or more metals.
8. Two alloys I use regualry are steel and bronze. I use steel when I drive, and Bronze when I pay with coins. Steel is an alloy made of primarly iron, with carbon and small amounts of other elements. Bronze is an alloy primarily copper, with tin, zinc, and other elements.
9. Carbon is a nonmetal that is a component of both steel and stainless steel.
10. Steel: Fe3C
8. Two alloys I use regualry are steel and bronze. I use steel when I drive, and Bronze when I pay with coins. Steel is an alloy made of primarly iron, with carbon and small amounts of other elements. Bronze is an alloy primarily copper, with tin, zinc, and other elements.
9. Carbon is a nonmetal that is a component of both steel and stainless steel.
10. Steel: Fe3C
- Properties of steel are often determined by carbon content. High-carbon steel is hard and brittle; low-or-medium-carbon steel can be welded and shaped.
- Steel is used in automobile and airplane parts, kitchen utensils, plumbing fixtures, and architectural decoration.
11. Semiconductors are found on columns 12 and 14. They are metalloids and are mostly located on the ladder in the periodic table.
12. Three elements commonly used for doping semiconductors are phosphorous, aluminum, and arsenic.
13. The primary use of the products of semiconductor technology is that it has electrical conductivity between that of conductors and nonconductors at normal temperatures. Elements with semiconducting properties include germanium (Ge), gallium arsenide (GaAs), and cadmium sulfide (CdS).
Wednesday, July 17, 2013
Quick Blog Question
Oxygen exists as two allotropes: O2
oxygen gas O3 ozone. O2 makes 20% of the air we breathe.
O3 is a gaseous substance found in the upper layers of our planet's atmosphere, as well as in some of the air pollution associated with cities.
O3 is a gaseous substance found in the upper layers of our planet's atmosphere, as well as in some of the air pollution associated with cities.
18-21 p. 182, 1-6 p.204
18. The difference between reusing and recycling is that recycling is converting waste into usable material, and reusing is to use more than once.
19. a. renewable resources: solar energy, wind power, tides, hydroelectricity
b. nonrenewable resources: petroleum, coal, natural gas, nuclear energy
20. a. reusing
b. recycling
c. reusing
21. They are both made, packed, shipped, used, disposed, and hopefully recycled.
1. allotrope: two or more forms of an element in the same state that have distinctly different physical and/or chemical properties.
 |
| allotropes of carbon |
2. oxygen:O2
oxygen gas O3 ozone
sulfur
 |
| allotropes of sulfur |
3. a. How their properties are different is because they all contain carbon just in different forms of the element,
b. Why their properties are different because they have distinctly different atomic arrangements.
c. What accounts for the differences in the cost of these items are the reactivity, abundance, and need for the item.
4. Engineered materials are more likely to be more stable and sturdier than natural materials because of the other material that they put in it.
5. Two advantages: low chemical reactivity and resistance to wear.
Two disadvantages; brittleness and they can fracture if exposed to rapid temperatures.
 |
| ceramics at a high temperature |
6 Two properties that can be modified in plastics to make them useful for new applications are making them safe to be exposed to sunlight and to resist wear and tear.
Tuesday, July 16, 2013
Quick Blog Question
A neutron is a particle without electrical charge; found in the nucleus of an atoms, along with a proton, which is a particle possessing a positive electrical charge. An electron is a particle possessing a negative electrical charge; they surround the nuclei of atoms. An atoms consists of a nucleus, protons, and electrons and is the smallest particle possessing the properties of an element. A molecule is the smallest particle of a substance retaining all the properties of that substance. CO2 and H20 are molecules.
13-21 p. 181
13. a.6 moles
b. 5 moles
c. 5 moles
14. a. 1 mole
b. 621grams
c. 28 grams
d. 223 grams
15. The percent oxygen by mass is not 67% because oxygen weighs more.
16. a. 216 + 32= 248 216/248 x 100= 87%
b. 54 + 48 = 102 54/102 x 100= 53%
c. 40+12+48= 100 40/100x100= 40%
17. a. 207+32+ 64= 303 207/303x100= 68%
b. 10%
c. 6%
18. The difference between reusing and recycling is that recycling is converting waste into usable material, and reusing is to use more than once.
19. a. renewable resources: solar energy, wind power, tides, hydroelectricity
b. nonrenewable resources: petroleum, coal, natural gas, nuclear energy
20. a. reusing
b. recycling
c. reusing
21. They are both made, packed, shipped, used, disposed, and hopefully recycled.
b. 5 moles
c. 5 moles
14. a. 1 mole
b. 621grams
c. 28 grams
d. 223 grams
15. The percent oxygen by mass is not 67% because oxygen weighs more.
16. a. 216 + 32= 248 216/248 x 100= 87%
b. 54 + 48 = 102 54/102 x 100= 53%
c. 40+12+48= 100 40/100x100= 40%
17. a. 207+32+ 64= 303 207/303x100= 68%
b. 10%
c. 6%
18. The difference between reusing and recycling is that recycling is converting waste into usable material, and reusing is to use more than once.
19. a. renewable resources: solar energy, wind power, tides, hydroelectricity
 |
20. a. reusing
b. recycling
c. reusing
 |
| recycling plant |
21. They are both made, packed, shipped, used, disposed, and hopefully recycled.
Quick Blog Question
My rare Earth metal is yttrium. The largest use of yttrium is in the form of yttrium(Ill) oxide, which is used to produce phosphors which give the red colour in colour television tubes. It is also used in the making of microwave filters, and many other appliences. Yttrium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements and bastnaesite by reduction with calcium metal. Yttrium reacts with cold water slowly and with hot water very rapidly. It dissolves in both acids and alkalis. Solid yttrium metal does not react with oxygen in the air.
Monday, July 15, 2013
1-12 p. 180
1. Law of Conservation of Matter: matter is neither created nor destroyed in any chemical reaction or physical change.
2. Scientific Law: summarizes what has been learned by careful observation of nature.
3. They are misleading because "using up"and "throwing away" sound the opposite of the law of conservation of matter, which is that no matter in created nor destroyed. "Using up" means that materials are chemically changed, not destroyed.
4. a. Reactants Sn: 1, H:1, F:1 Products: Sn:1, F: 2, H:2 This equation is not chemically balanced.
b. Reactants Si: 1, O: 2, C: 1 Products: Si: 1, C: 2, O: 1 This equation is not chemically balanced.
c. Reactants Al: 1, O: 3, H: 6, Cl: 3 Products: Al: 1, O: 3, H: 6, Cl: 3 This equation is chemically balanced.
5. a. 3
b. 2
c. 1
6. a. 1 WO3 + 3 H2 ---à 1 W + 3 H20
b. 2 PbS + 3 O2 ---à 2 PbO + 2 SO2
c. 4 Fe + 3 O2 ---à 2 Fe2O3
7. a. 1 Ca3 (PO4)2 + 3H2SO4 ---à 2H3PO4 + 3CaSO4
b. C8H18 + 13O2 ---à 8CO2 + 9H20
8. a. Na: 2, S:1, O: 4, K:2, Cl:1---> Na:2, S:1, O: 4, K: 2, Cl: 1
b. Yes
9. 5
10. a. 32g
b. 48g
c. 100g
d. 58g
e. 180g
11. They can both represent a mole because a mole is just the amount of an element that you can use in a lab.
12. a. 19 atoms
b. 9.5 atoms
c. 1.9 atoms
d. 1 atom
2. Scientific Law: summarizes what has been learned by careful observation of nature.
3. They are misleading because "using up"and "throwing away" sound the opposite of the law of conservation of matter, which is that no matter in created nor destroyed. "Using up" means that materials are chemically changed, not destroyed.
4. a. Reactants Sn: 1, H:1, F:1 Products: Sn:1, F: 2, H:2 This equation is not chemically balanced.
b. Reactants Si: 1, O: 2, C: 1 Products: Si: 1, C: 2, O: 1 This equation is not chemically balanced.
c. Reactants Al: 1, O: 3, H: 6, Cl: 3 Products: Al: 1, O: 3, H: 6, Cl: 3 This equation is chemically balanced.
5. a. 3
b. 2
c. 1
6. a. 1 WO3 + 3 H2 ---à 1 W + 3 H20
b. 2 PbS + 3 O2 ---à 2 PbO + 2 SO2
c. 4 Fe + 3 O2 ---à 2 Fe2O3
7. a. 1 Ca3 (PO4)2 + 3H2SO4 ---à 2H3PO4 + 3CaSO4
b. C8H18 + 13O2 ---à 8CO2 + 9H20
8. a. Na: 2, S:1, O: 4, K:2, Cl:1---> Na:2, S:1, O: 4, K: 2, Cl: 1
b. Yes
9. 5
10. a. 32g
b. 48g
c. 100g
d. 58g
e. 180g
11. They can both represent a mole because a mole is just the amount of an element that you can use in a lab.
12. a. 19 atoms
b. 9.5 atoms
c. 1.9 atoms
d. 1 atom
Rare Earth Metals Report by Kourosh, Merry, Ricardo :)
History: Yttrium was discovered by Johan Gadolin, a Finnish chemist, in 1794 while analyzing the composition of the mineral gadolinite ((Ce, La, Nd, Y)2FeBe2Si2O10) in 1789. Yttrium is named after Ytterby, Sweden. Yttrium is a highly crystalline iron-gray, rare-earth metal.
| Johan Gadolin |
Uses:
1. The largest use of yttrium is in the form of yttrium(Ill) oxide, which is used to produce phosphors which give the red colour in colour television tubes.
2. It is also used in the making of microwave filters.
3. Yttrium is often used as an additive in alloys, and increases the strength of aluminium and magnesium alloy.
4. It is also used as a detoxifier for non-ferrous metals. It has been used as a catalyst in ethylene polymerisation.
5. Yttrium-90, a radioactive isotope, has a medical use in needles which have replaced the surgeon’s knife in killing pain-transmitting nerves in the spinal cord.
| phosphors give the red colour in colour television tubes |
Process: Today, yttrium is primarily obtained through an ion exchange process from monazite sand ((Ce, La, Th, Nd, Y)PO4), a material rich in rare earth elements and bastnaesite by reduction with calcium metal.
Physical Properties: In 1843, Carl Mosander investigated yttrium oxide more thoroughly and found that it consisted of three oxides: yttrium oxide, which was white; terbium oxide, which was yellow; and erbium oxide, which was rose-coloured. It is a silvery metal, which is stable in air because of an oxide film that forms on its surface.
39
Atomic mass
88.9059 g.mol -1
Electronegativity according to Pauling
1.2
Density
4.47 g.cm-3 at 20°C
Melting point
1500 °C
Boiling point
3336 °C
Chemical Properties: Yttrium reacts with cold water slowly and with hot water very rapidly. It dissolves in both acids and alkalis. Solid yttrium metal does not react with oxygen in the air. However, it reacts very rapidly when in its powdered form. Yttrium powder may react explosively with oxygen at high temperatures.
Neodymium
Atomic Number: 60
Atomic Weight: 144.242
Melting Point: 1294 K (1021 C)
Boiling Point: 3347 K (3074 C)
Density: 7.01
Room Temperature State: Solid
Discovery
Neodymium was discovered in 1885 by a researcher named Carl F. Auer. He obtained the rare earth metal through an ion exchange with a common chemical in some rare earth metals, monazite sand.
Physical Properties:
-Bright, silvery look to it
-Very reactive
-Oxidizes in air
Chemical Properties:
-Tarnishes slowly in air
-Very easy to burn
-Reacts slowly in cold water
-Very reactive with all the halogens
Uses:
Neodymium is used as fertilizer in China. Many compounds of rare earth metals are used in China for fertilization because they promote plant growth, similar to Ca2+. It is also used in samarium-neodymium dating, which is a very exact and useful process for determining the age of rocks and meteors. Another use for the element is in determining the size and strength of a volcanic eruption. By scanning the neodymium isotopes in the volcano, scientists can warn the residents living near the volcano of the intensity of the upcoming eruption.
One of the most common uses for neodymium is in magnets. Neodymium magnets are the strongest permanent magnets known to man, and can lift a thousand times its own weight. They are very cheap to make and fairly light as well, making them better and more useful than the samarium-cobalt magnets. The magnets are used in a multitude of products:
-microphones
-speakers
-in-ear headphones and normal headphones
-guitar and bass guitar pick-ups
-hard disks
Neodymium magnet motors were created in 2010, and are now replacing many motors. They are electric, and can be found in hybrid cars and wind turbines.
We know neodymium for its use in iPhone screen color. Neodymium, being highly reactive, reacts with of elements to create the thousands of different colors we see on our iPhone screens.
Occurrence:
Neodymium is not in the least bit rare. The main countries that mine neodymium is China, Australia, Brazil, and the United States. It is estimated that the reserves of neodymium that are still not mined are 8 million tonnes. In the Earths crust, neodymium's abundance is about 10% - 18%. It is the most common rare earth metal, besides cerium present in the earth's crust.
Uranium
Uranium Production:
World-wide uranium productions amounted to 50,572 tonnes. Kazakhstan, Canada, and Australia are the top three producers and together account for 63% of world uranium production. Other major Uranium Producing Countries are Namibia, Russia, Niger, Uzbekistan, and the United States producing about 1000 tonnes per year are
Uranium Uses
The most common use of Uranium is to power nuclear plants. As of 2008, known uranium ore resources that can be mined at about current costs are estimated to be sufficient to produce fuel for about a century, based on current consumption rates.
Uranium History
The use of uranium in its natural oxide form dates back to at least the year 79 CE, when it was used to add a yellow color to ceramic glazes. Yellow glass with 1% uranium oxide was found in a Roman villa on Cape Posillipo in the Bay of Naples, Italy by R. T. Gunther of the University of Oxford in 1912. Starting in the late middle Ages, pitchblende was extracted from the Habsburg silver mines in Joachimsthal, Bohemia (now Jáchymov in the Czech Republic) and was used as a coloring agent in the local glassmaking industry. In the early 19th century, the world's only known sources of uranium ore were these mines.
Physical/Chemical Properties
Uranium is a hard, dense, malleable, ductile, silver-white, radioactive metal. Uranium metal has very high density. When finely divided, it can react with cold water. In air it is coated by uranium oxide, tarnishing rapidly. It is attacked by steam and acids. Uranium can form solids solutions and intermetallic compounds with many of the metals.
Abundance:
Uranium is very abundant. In fact, the world’s largest known resources increased by 15% in the last two years.
Sunday, July 14, 2013
9-22 p. 151
9. Active metals are more difficult to process and refine than are less active metals because they react with more minerals than non-reactive metals, and they require more energy.
10. Copper and Silver
11. Metals exist in nature as minerals rather than as pure metallic elements because they are unstable and combine with elements
12. a. Calcium is more reactive than chromium.
13. b. In the second equation, the atoms and charges are balanced.
14. a. It would be a bad idea to do that because iron is more reactive than lead nitrate, and a reaction would occur. The iron would dissolve the lead.
b. Fe3 + Pb2 --à Fe2 + Pb3
15. Oxidation is any process in which one or more electrons cane considered as lost by a chemical species. Reduction is any process in which one or more electrons can be considered as gained by a chemical species.
16. a. Au3+ + 3e --à Au
10. Copper and Silver
11. Metals exist in nature as minerals rather than as pure metallic elements because they are unstable and combine with elements
12. a. Calcium is more reactive than chromium.
13. b. In the second equation, the atoms and charges are balanced.
14. a. It would be a bad idea to do that because iron is more reactive than lead nitrate, and a reaction would occur. The iron would dissolve the lead.
b. Fe3 + Pb2 --à Fe2 + Pb3
15. Oxidation is any process in which one or more electrons cane considered as lost by a chemical species. Reduction is any process in which one or more electrons can be considered as gained by a chemical species.
16. a. Au3+ + 3e --à Au
Gold ion gold metal
b. V--à
V+ + 1e-
elemental vanadium vanadium ions
c. Cu --à
Cu2+ + 2e-
17. a. Reduction
b. Oxidation
c. Reduction
18. a. Zinc because it has lost two electrons
b. Nickel because it gained two electrons
c. Zinc is the reducing agent.
19. a. Potassium because it lost 1 electron.
b. Mercury because gained two electrons
c. Potassium is the oxidizing agent.
20. a. Al + Cr3 -à
Al3- + Cr
b. Mn2+ Mg --à
Mg2-
21. Electrometallurgy: the use of electrical energy to add electrons to metal ions, thus reducing them.
Pyrometallurgy: the use of high temperatures (thermal energy) to process metals or their ores.
Hydrometallurgy: the industrial extraction of metals from ores at ordinary temperatures by water- based process.
22. a. Magnesium: elctrometallurgy
b. Lead: pyrometallurgy
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