1.
a. 1 repeating unit
b. 2 repeating units
c. 3 repeating units
d. 500-20,000 or more repeating units
3. Natural polymers: medicines, food additives, cotton, and silk
Synthetic polymers: celluloid, shellac, nylon, plastic toys
6. The term unsaturated is used to describe the structures of alkenes and alkynes because not all carbon atoms are bonded to their full capacity with four other atoms.
13. See drawing
11.
a. ii
b. iii
c.
d. ii
12. The other 75% is lost in heat, and this is why the engine is so inefficient.
Wednesday, July 24, 2013
Homework 7/23/13
31.
a. Propane, C3H8
b. Pentane, C5H12
32. -ane implies that hexane is an alkane.
33. Yes, each of these molecules are isomers of one another. They are composed of the same number of atoms, they are just arranged differently.
34. See drawing
35. Butane is the shortest-chain alkane that can demonstrate isomerism because it has four carbon atoms.
36. Both representations are correct because although their atoms are in different arrangements, the molecular formulas are the same. The molecules would be structural isomers of each other.
37.
a. See drawing
b. The straighter the chain, the higher the boiling point. Thus, the branched chain molecule would have a lower boiling point.
38. A short straight chain, and a short branched chain would have a lower boiling point, because the shorter the chain, the lower the boiling point. The short branched chain would have a lower boiling point than a long straight chain because straight chains have a stronger intermolecular force which causes a higher boiling point than branched chains.
1. Petroleum is sometimes cosidered "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, which is ready to be released. An example of potential energy is the energy within a skate board on top of a hill.
b. Kinetic energy is energy related to motion. The skateboard going down the hill represents 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.
a. Propane, C3H8
b. Pentane, C5H12
32. -ane implies that hexane is an alkane.
33. Yes, each of these molecules are isomers of one another. They are composed of the same number of atoms, they are just arranged differently.
34. See drawing
35. Butane is the shortest-chain alkane that can demonstrate isomerism because it has four carbon atoms.
36. Both representations are correct because although their atoms are in different arrangements, the molecular formulas are the same. The molecules would be structural isomers of each other.
37.
a. See drawing
b. The straighter the chain, the higher the boiling point. Thus, the branched chain molecule would have a lower boiling point.
38. A short straight chain, and a short branched chain would have a lower boiling point, because the shorter the chain, the lower the boiling point. The short branched chain would have a lower boiling point than a long straight chain because straight chains have a stronger intermolecular force which causes a higher boiling point than branched chains.
1. Petroleum is sometimes cosidered "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, which is ready to be released. An example of potential energy is the energy within a skate board on top of a hill.
b. Kinetic energy is energy related to motion. The skateboard going down the hill represents 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 energy.
b. Potential energy.
c. Kinetic energy.
d. Potential energy.
e. Kinetic energy.
b. Potential energy.
c. Kinetic energy.
d. Potential energy.
e. Kinetic energy.
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. More energy is released than is required to begin the chemical reaction.
b. Endothermic. More energy is required to crack large hydrocarbon molecules than is released.
c. Endothermic. It takes more energy to digest a candy bar than the energy released after digestion.
b. Endothermic. More energy is required to crack large hydrocarbon molecules than is released.
c. Endothermic. It 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 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.
Monday, July 22, 2013
pg. 3441.
1. Because infrared radiation is mostly heat energy, exposure to it is not as harmful as exposure to ultraviolet light, which is the most energetic form of sun radiation. Ultraviolet light can cause sunburns and skin cancer and can even sterilize materials by killing bacteria and destroying viruses (UV-C radiation).
2. Visible solar radiation provides the energy needed for photosynthesis and the visible scattering of light during sunset.
3. Since there is less water vapor, and therefore, less greenhouse gas caused by water vapor in dry and arid regions such as New Mexico and Arizona, 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. This results in wider air-temperature fluctuations from night to day than states with more humid conditions, for not as much heat is stored in the clouds.
4.
a. The daytime temperatures would be much cooler, because with less greenhouse gases, 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.
pg. 350
1. A hydrocarbon is a molecular compound that only contains atoms of hydrogen and carbon.
2. Petroleum is not only a nonrenewable resource, but a very versatile material that is used both as fuel that can be converted to gasoline; therefore, it can be used as heat sources, can deliver energy to generate electricity, can generate energy, and is also used to produce useful every day products, it is a valuable resource.
3. Oil is crude because it is pumped from underground and using it in a natural state without some degree of refinement where it is separated into simpler mixtures is not possible (through fractional distillation).
6.
a. 2,200,000 barrels
b. 17,800,000 barrels
7. Heating and cooking fuel, petrochemicals, kerosene, diesel fuel oil, lubricating oil and grease, heavy oils and wax, petroleum jelly, road oils and asphalt, petroleum coke.
8.
a. Water bottle, sports equipment, clothing, 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 (although it is much better to make them out of plastic).
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 with each other.
13. Water and acetone would be the easiest to separate from each other by distillation. This is because since 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 does not separate each compound in crude oil, but produces several distinctive mixtures, called fractions. Fractional distillation is also a continuous process. The crude oil is heated in a furnace and then pumped into the fractionating tower. The temperature within the tower (distilling column) is highest at the bottom and decreases towards the top. Smaller and lighter molecules that have lower boiling points vaporize to the top of the tower, and fractions with larger molecules with higher boiling points condense back to liquid in trays in the lower part of the column. Substances with the highest boiling points never vaporize, but drain from the base—bottoms.
17.
1. Because infrared radiation is mostly heat energy, exposure to it is not as harmful as exposure to ultraviolet light, which is the most energetic form of sun radiation. Ultraviolet light can cause sunburns and skin cancer and can even sterilize materials by killing bacteria and destroying viruses (UV-C radiation).
2. Visible solar radiation provides the energy needed for photosynthesis and the visible scattering of light during sunset.
3. Since there is less water vapor, and therefore, less greenhouse gas caused by water vapor in dry and arid regions such as New Mexico and Arizona, 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. This results in wider air-temperature fluctuations from night to day than states with more humid conditions, for not as much heat is stored in the clouds.
4.
a. The daytime temperatures would be much cooler, because with less greenhouse gases, 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.
pg. 350
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.
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.
pg. 233
1. A hydrocarbon is a molecular compound that only contains atoms of hydrogen and carbon.
2. Petroleum is not only a nonrenewable resource, but a very versatile material that is used both as fuel that can be converted to gasoline; therefore, it can be used as heat sources, can deliver energy to generate electricity, can generate energy, and is also used to produce useful every day products, it is a valuable resource.
3. Oil is crude because it is pumped from underground and using it in a natural state without some degree of refinement where it is separated into simpler mixtures is not possible (through fractional distillation).
6.
a. 2,200,000 barrels
b. 17,800,000 barrels
7. Heating and cooking fuel, petrochemicals, kerosene, diesel fuel oil, lubricating oil and grease, heavy oils and wax, petroleum jelly, road oils and asphalt, petroleum coke.
8.
a. Water bottle, sports equipment, clothing, 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 (although it is much better to make them out of plastic).
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 with each other.
13. Water and acetone would be the easiest to separate from each other by distillation. This is because since 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 does not separate each compound in crude oil, but produces several distinctive mixtures, called fractions. Fractional distillation is also a continuous process. The crude oil is heated in a furnace and then pumped into the fractionating tower. The temperature within the tower (distilling column) is highest at the bottom and decreases towards the top. Smaller and lighter molecules that have lower boiling points vaporize to the top of the tower, and fractions with larger molecules with higher boiling points condense back to liquid in trays in the lower part of the column. Substances with the highest boiling points never vaporize, but drain from the base—bottoms.
17.
Light: Aviation gasoline and motor gasoline, kerosene, and refined oils.
Intermediate: Gas oil, petrochemicals, heavy furnace oil, and diesel fuel oil.
Heavy: Lubricating oil and grease, heavy oils and wax, and cracking stock.
18. The fraction with the highest boiling point range would be removed at the bottom. This is because they are thick (viscous) liquids that never vaporize, called bottoms; they drain from the tower’s base.
19. A way to further separate the components of each fraction would be through distillation after a fractional distillation.
20. Methane (CH4), pentane (C5H12), hexane (C6H14), octane (C8H18).
The boiling points increase with greater amounts carbon atoms within the straight-chains of hydrocarbons; the higher the boiling point, the stronger the intermolecular forces are between the molecules.
21. A covalent bond is the sharing of two or more valence electrons between two atoms, allowing both atoms to fill their outer shells completely.
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
Intermediate: Gas oil, petrochemicals, heavy furnace oil, and diesel fuel oil.
Heavy: Lubricating oil and grease, heavy oils and wax, and cracking stock.
18. The fraction with the highest boiling point range would be removed at the bottom. This is because they are thick (viscous) liquids that never vaporize, called bottoms; they drain from the tower’s base.
19. A way to further separate the components of each fraction would be through distillation after a fractional distillation.
20. Methane (CH4), pentane (C5H12), hexane (C6H14), octane (C8H18).
The boiling points increase with greater amounts carbon atoms within the straight-chains of hydrocarbons; the higher the boiling point, the stronger the intermolecular forces are between the molecules.
21. A covalent bond is the sharing of two or more valence electrons between two atoms, allowing both atoms to fill their outer shells completely.
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
Sunday, July 21, 2013
Homework 7/21/13
1. The frequency of electromagnetic radiation/photons and energy are directly proportional because the wavelength of electromagnetic radiation/photons and energy are inversely proportional.
2. Spectrum is a good descriptor of the types of energy found in electromagnetic radiation because the spectrum shows the range of energy from high to low.
3. Visible light is useful in plant photosynthesis because visible radiation can energize electrons in some chemical bonds which provides energy needed for photosynthesis reactions.
4.
a. Infrared, visible, ultraviolet
b. Infrared radiation is essentially heat energy, which warms living things. Visible radiation can energize electrons in chemical bonds. Although ultraviolet radiation can cause sunburns, skin cancer, and can kill bacteria and destroy viruses, it is necessary for humans in some amounts, for exposure to it results in the production of vitamin D.
5. UV-C photons have enough energy to break covalent bonds, and therefore, lead to chemical changes in the materials exposed to radiation; UV-C radiation can kill bacteria and destroy viruses, as it can damage other living organisms.
6. Two natural major greenhouse gases, carbon dioxide and water vapor, absorb infrared radiation and reradiate the energy back to earth. On a clear day, 90% of visible radiation directed towards earth travels to Earth's surface. UV-C radiation is absorbed in the stratosphere before reaching earth's surface and most UV-A and UV-B radiation us absorbed by the stratospheric ozone layer (and does not reach the earth's surface).
7. When more greenhouse gases are produced, such as carbon dioxide and water vapor, more infrared radiation is absorbed. This results in more energy reradiated on earth's surface, hotter water affecting the hydrologic cycle (more water vapor produced), and an overall hotter earth.
8.
a. An asphalt, such as snow, sand, or concrete, warms up more quickly when exposed to sunlight. This is because when solar radiation strikes these materials, it is reflected and illuminated back into space. On the other hand, lake water does reflect light, but also stores absorbs and stores heat.
b. Water, in forms like water vapor, act as greenhouse gases and absorb infrared light and reradiate it back to earth's surface. Asphalts directly reflect light sources back into space.
14. This infrared radiation is not directly from the sun, but is the product of transformed UV and visible radiation from the sun within the clouds. Infrared radiation is essentially heat energy, that these greenhouse gases have made from trapping UV and visible light in order to absorb, reradiate, and reflect the heat energy onto earth's surface.
15.
a.
Natural: 1. breathing; 2. bacterial decay.
Human: 1. agricultural and industrial activities; 2. burning of fossil fuels.
b.
Natural: 1. decomposition of plants; 2. decomposition of animal wastes
Human: 1. Refining fossil fuels; 2. raising of livestock.
16.
a. lower altitude, increase in greenhouse/atmospheric gases, higher air pressure.
b. higher altitude, decrease in greenhouse/atmospheric gases, lower air pressure.
b. higher altitude, decrease in greenhouse/atmospheric gases, lower air pressure.
17. What goes on in greenhouse with transparent glass imitates the way the greenhouse gases transform UV and visible radiation to IR radiation within clouds, and reradiate and reflect the heat energy within earth, or the greenhouse (since the infrared light cannot escape through the glass, like earth's CO2 and H2O gas that act as a shield). This is why on a sunny winter day, a greenhouse with transparent glass walls is much warmer than is a structure with opaque wooden walls.
18.
19. Three chemical reservoirs of carbon atoms include atmospheric CO2 gas, solid calcium carbonate (CaCO3) in limestone, and organic molecules.
20. Carbon naturally moves within Earth's systems. The carbon atom could be part of the atmosphere as a gas as a result of photosynthesis, in the lithosphere as plant or animal waste decay, or part of the hydrosphere as limestone.
Thursday, July 18, 2013
Homework 7/18/13
7. An alloy is a solid combination of atoms of two or more elements.
8. Steel and 14-karat gold.
9. Carbon is a component of both steel and stainless steel.
10.
Nickel aluminide
Formula: Ni3Al
Use: component of jet aircraft engines
Physical property: low density, strong, metallic
11. Elements that behave as semiconductors are located on the right side of the periodic table, in-between metals and nonmetals, the metalloids.
12. Three elements commonly used for doping semiconductors are phosphorus, arsenic, and aluminum.
13. The primary use of the products of semiconductor technology is to allow computers to process digital information.
8. Steel and 14-karat gold.
9. Carbon is a component of both steel and stainless steel.
10.
Nickel aluminide
Formula: Ni3Al
Use: component of jet aircraft engines
Physical property: low density, strong, metallic
11. Elements that behave as semiconductors are located on the right side of the periodic table, in-between metals and nonmetals, the metalloids.
12. Three elements commonly used for doping semiconductors are phosphorus, arsenic, and aluminum.
13. The primary use of the products of semiconductor technology is to allow computers to process digital information.
Wednesday, July 17, 2013
Homework 7/17/13
1. Allotropes are different forms of an element that each have distinctly different physical or chemical properties, but whose forms are in the same state.
2. Oxygen and boron form allotropes.
3.
a. A diamond is the hardest substance known, not electrically conductive, has an extremely high melting point, and is expensive. Coal is combustible and cheap. Pencil lead is a useful lubricant, a conductor of electricity, extremely soft, common, cheap, and made out of graphite.
b. Their properties are different because although they are made of the same element, they are allotropes of carbon, and therefore, have very different atomic arrangements.
c. The rigid, three dimensional structure of carbon atoms in diamonds indicates its high melting point, hardness, and rareness that accounts for its high cost. The atomic makeup of graphite and coal indicate their much more common, more reactive, and softer properties, and therefore, their cheaper prices.
4.While the makeup of natural materials is uncontrolled and untouched, engineered materials are developed to enhance natural materials through manufacturing methods that carefully control the microstructure of the materials.
5. The advantages of ceramics are that they are durable. have high melting points, and strength and high temperatures. The disadvantages of ceramics are that they are brittle and when rapidly exposed to high or low temperatures, the will crack.
6. Polyethylene can be tailored to display soft properties, such as a squeeze bottle for water, or tailored to be hard and brittle, like glass. Plastic can also be made into optical fibers, which replace copper wires and provide fantastic and noise free communication systems with high capacities.
2. Oxygen and boron form allotropes.
3.
a. A diamond is the hardest substance known, not electrically conductive, has an extremely high melting point, and is expensive. Coal is combustible and cheap. Pencil lead is a useful lubricant, a conductor of electricity, extremely soft, common, cheap, and made out of graphite.
b. Their properties are different because although they are made of the same element, they are allotropes of carbon, and therefore, have very different atomic arrangements.
c. The rigid, three dimensional structure of carbon atoms in diamonds indicates its high melting point, hardness, and rareness that accounts for its high cost. The atomic makeup of graphite and coal indicate their much more common, more reactive, and softer properties, and therefore, their cheaper prices.
4.While the makeup of natural materials is uncontrolled and untouched, engineered materials are developed to enhance natural materials through manufacturing methods that carefully control the microstructure of the materials.
5. The advantages of ceramics are that they are durable. have high melting points, and strength and high temperatures. The disadvantages of ceramics are that they are brittle and when rapidly exposed to high or low temperatures, the will crack.
6. Polyethylene can be tailored to display soft properties, such as a squeeze bottle for water, or tailored to be hard and brittle, like glass. Plastic can also be made into optical fibers, which replace copper wires and provide fantastic and noise free communication systems with high capacities.
Homework 7/16/13
13.
a.
6 moles
b.
5 moles
c.
5 moles
14.
a.
2 moles
b.
621 grams
c.
28 grams
d.
mass of 446 grams
15. Even though the percent of the oxygen atoms is 67%, since oxygen's molar
mass is 32 and carbon's molar mass is 12 in this molecule, The percent oxygen
by mass 32g/44g x 100%, or 73%.
16.
a.
total molar mass is 248, metal molar mass is 216.
216/248=
87%
b.
total molar mass is 102, metal molar mass is 54.
54/102=
53%
c.
total molar mass 100, metal molar mass is 40
40/100=
40%
17.
a.
total molar mass is 303, lead molar mass is
207
207/303=68%
b.
5/50= 10%
c.
68*.10=6.8%
18.
a.
Reusing is the use of the same item multiple times for the same, or different
tasks the item is applicable to. Recycling is when an item is reprocessed into
a a different item made of parts, or all of the same substances.
b.
Reusing:
water bottles, plastic containers, paper.
Recycling: Cans, paper, glass,
plastic.
19.
a.
water, air, soil, water, plants
b gold, silver, copper, natural gas
20.
a.
reusing.
b.
recycling.
c.
reusing.
21. Both glass from a light bulb and
paper from a newspaper can be recycled. In since paper that is not recycled
leaves a high proportion of combustibles as waste, the newspaper can be sent to
a waste-to-energy plant to produce energy that can be used to power the light
bulb.
Subscribe to:
Posts (Atom)