Homework #5 week two semester two

1. An alloy is a solid combination of atoms of two or more elements.
2. Two examples of alloys I use regularly are 14 karat gold (in jewelry) and stainless steel (refrigerator door).
3. The nonmetal that is a component of both steel and stainless steel is Carbon ( C)
4. The formula, use, and an important physical properties of an alloy that I also a well-defined compound:
1. Cr₃Pt (chromium-platinum)
2. Used to form the basis of some commercial razor blade edges.
3. It has a constant, definite ratio of metallic atoms
5. The periodic table location of elements that behave as semiconductors is in the metalloid section because they are not fully conductive like metals, yet they aren’t completely nonconductive like nonmetals.
6. Three elements that are commonly used for doping semiconductors are Phosphorous, arsenic, and Aluminum
7. The primary uses of the products of semiconductor technology are as transistors and integrated computer circuits.

Homework #4 week two semester two

1. The difference between reusing and recycling is that reusing means taking parts or sections and of the old substance and using them as part of something new or using them in a new creative way; recycling is taking something old and melting it down to turn it into something new completely
1. Two examples of substances that are recyclable are newspapers and water bottles; two examples of substance that are reusable are old clothes and old computer parts.
2. Four examples of:
1. Renewable resources: solar power, wind energy, biodiesel fuel, and geothermal electric energy.
2. Nonrenewable resources: petroleum, coal, metal, and natural gas
3. Classify as reusing or recycling:
1. Reusing
2. Recycling
3. Reusing
4. The life cycle of a light bulb has a very different process than that of a newspaper. Obtaining the resources, producing the product, makes the newspaper and recycling while a light bulb may be used from different recycled products. Also newspaper uses renewable resources while a light bulb is not.

Copper retrieval lab

Observation:

Before: Powdery with some solids. Black and it has a little copper color in it too.

After adding Hydrochloric solution: It is becoming harder, some more solids are forming,. It is starting to look like copper again

Filter paper: .98

Zinc: Bubbling, and its starting to turn black, dissolving, copper is coming out. Solid copper is forming on the zinc. It looks like corals.

Question:

1. During Investigation. Matter B.3, not all of the original copper powder reacted when you heated it in air.
1. A. What observational evidence leads you to think that the reaction was incomplete? Not all of the copper is dissolved.
2. How would you revise the procedure so that more copper oxide could form? React copper more

2. a. The mass of the original powdered copper that reacted was 1.36g
b. The percent of the total copper sample reacted 189% (this number may be incorrect because some small amounts of zinc might have still been present, which altered the weight)

3. In the reaction between copper chloride solution and zinc metal, in Investigation. Cu^2+ ion gained two electrons to form an atom of copper metal. Each zinc metal atom lost two electrons to form a Zn^2+

a. Write a balance chemical equation that represents this process:

CuCl+Zn-à Zn^2+Cl + Cu

B. Zinc+ Oxidized

Reactant reduced is copper chloride

The reducing agent: Coper Chloride

The oxidizing agent: Zinc

4

a. .After adding zinc the color became cloudy white

b. The reaction between copper and the zinc when the zinc is less reactive than copped, its going to change the copper ion back into the copper metal

c.The color results in the copper ion going into solution.

b. The hydrochloric acid

Each resource when into solution

Solar power from space: beam it down

Solar power has long been an option to reduce consumption of coal as Earth’s only energy source, yet what if people could use the intense solar rays directly from space? With the new technology, that is currently being investigated, more solar power than we would be able to grasp on Earth may be at our fingertips. Space enthusiasts believe the space- based-solar collector could obtain about 5 times as much solar power as that on Earth. When solar energy enters our atmosphere it comes in contact with air and is less concentrated then out in space; therefore, scientists believe if they find the correct window for entry they can magnify the solar energy by beaming it down directly from a satellite. However, at the moment this dream is out of reach due to the extreme costs of the satellites and their transportation to space, but hopeful scientists are anticipating the satellites use in a couple of years; the satellites would be specialized to give power to special companies like military and rescue workers. This summer many of the scientists’ dreams may become reality as the first satellite is tested with microwaves to see if it will be ready for the harsh powers of the sun. Dr Sweeny and his team at Astrium will be testing the satellite with a laser to see if the solar power will be able to concentrate as it enters Earth. The beam will be produced by a device called a fibre laser it generates the coherent light of a laser beam in the core of a long, thin optical fibre, which allows the beam produced to be of a higher quality than other laser beams. After the land test the proceeding test will be in space, yet this test will not be available for five more years and the probability that an orbiting power source will be in space in the next couple years is not likely; however, there is a slight possibility that there will be an orbiting power source in 10 years. Who knows maybe the future of complete renewable energy is knocking on Earth’s door.

http://www.economist.com/node/18864324

Homework #3 week two semester two

1. 6 moles of NH₃ are needed to react with h9 mol PbO
1. 5 moles N₂ are produced by the reaction of 9 mol NH₃
2. 5 moles Pb are produced from 5 mol PbO
2. 34 moles max can be produced from 34.0 g NH₃
1. 621g Pb
2. 62 g max N₂
3. 2 PbO ( 446.4)g
3. Because oxygen is a diatomic molecule (two atoms of O) the mass is 32 g not 16g and therefore 73 % of oxygen atoms make up CO₂
4. 87% of Ag is in Ag₂S
1. 53% of Al  is in Al₂O₃
2. 40% of Ca is in CaCO₃
5. 68% of Pb is in PbSO₄
6. 10% of PbSO₄  is in the ore
7. 57% of Pb is in the entire ore



10% of PbSO4 is in the ore



68% of Pb is in PbSO4

Homework #2 week one semester two

1. The law of conservation of matter states that atoms cannot be destroyed or created; therefore, all equations must be balanced always.
2. A scientific law is what has been observed and learned from nature.
3. “using up” and “throwing away” are misleading because according to the conservation of matter no atoms can be destroyed because the energy does not get destroyed it just gets transformed into a different substance.
4. Sn + HF becomes SnF₂ + H₂
1. Sn = 1             Sn=1
2. H = 1               H=2
3. F = 1               F = 2
4. This equation is not balanced because there are two Hydrogens and Flurines on the product side but only 1 of each on the reactant side.
5. SiO₂+ C becomes SiC + CO
1. Si = 1              Si = 1
2. O = 2               O = 1
3. C = 1               C = 2
4. The equation is not balanced because the Carbon atoms and the oygen atoms are unbalanced.
6. Al (OH)_3­ + 3 HCl becomes AlCl_3­ + 3 H₂O
1. Al = 1              Al = 1
2. O = 3               O = 3
3. H = 6               H = 6
4. Cl = 3              Cl = 3
5. The equation is balanced
7. N₂ + 3 H₂ becomes 2 NH₃
1. The coefficient of Hydrogen gas is 3
2. The coefficient of NH₃ gas is 2
3. The coefficient of nitrogen gas is 1
8. On paper
9.   1   Ca₃(PO₄)₂ +     3  H₂ SO₄ becomes    2  H₃PO₄ +  3    CaSO₄
1. Ca = 3                                     Ca = 3
2. P = 2                                       P = 2
3. O = 20                                       O = 20
4. H = 6                                       H = 6
5. S = 3                                       S = 3
10.         C₈H₁₈ +  14  O₂ becomes      8    CO₂ +   9    H₂O
1. C = 8                                       C= 8
2. H = 18                                     H = 18
3. O = 2                                       O = 28
11. Na = 2, S = 1, O = 4, K = 2, Cl = 1 becomes Na = 2, Cl = 1, K = 2, S = 1, O = 4
1. The student did not create a balanced equation because all the atoms are conserved properly, yet the student changed the subscripts when the coefficients are the only ones that are supposed to change.
12. ?
13. Molar mass of O₂ = 32, ozone = 48, CaCO_3­ = 100, Mg(OH) ₂ = 58 g, C₉H₈O_4­ = 180
14. The samples can both accurately represent 1 mol of each substance because 1 mol of a substance is a different measurement for each substance because each substance has a different atomic mass (= 1 mol).
15.  If one mole of potassium metal has a mass of 39.1 g:
1. There is 1 atom in 39.1 g potassium
2. There is .5 atoms in 19.55 g potassium
3. There is .1 atom in 3.91 g potassium
4. There is .03 atoms in 1.0 g of potassium

Metal repot: Au

Metal report: Gold

Katrina Cymerman

   Gold, an extremely precious metal turns out to have many uses though it is extremely rare to find it in nature at the present moment. The atomic symbol is Au for gold’s original Latin name aurum. Gold, in its natural state, has 79 electrons and 79 protons, and is known as one of the heavier elements on the periodic table due to the fact that the atomic mass is 197 g. Gold has many different uses: jewelry, U.S. coins, electric wiring, and (in a thin foil like form) on different space crafts. Gold has been seen as a precious metal throughout history; from the present to the ancient Egyptians gold has been used to decorate buildings as well as people and as a way to show wealth. Though known as a “noble metal” for its relatively low reactivity, gold is known to combine with different substances to form gold ores and alloys. Gold is mined throughout the world and usually found in its pure form. However, the gold nuggets that were once discovered in rivers to the cries of “Eureka!” are no longer as common because of the extensive demand for gold and the amount of the metal that is being mined each day.

• Characteristics of Gold (Au)
• Color
• Gold is known for its yellow metallic color and its high luster; however, there are some varieties to the color especially when mixed with different metals such as copper and silver, which give gold a reddish tint (rose gold).
• Ductile
• Gold is the most ductile of all the metals because it is also the most malleable of the metals. For example, an ounce of gold can be stretched into 300 square feet of wiring, which makes gold an ideal substance for electrical wiring.
• Malleability
• The malleability of gold makes it possible to be used in extremely thin forms. Some of the thinnest forms of gold are used for food as decorations and some are used for the gold foil in astronauts’ suits to protect them from the harsher conditions in space.
• Electrical conductivity
• Gold is an excellent conductor of electricity and is used in electric wiring due to this fact. However, gold is very pricey so it is not used often in wiring for wiring in peoples’ homes.
• Chemical reactivity
• Though known as a “noble metal” because gold does not react readily with many substances such as air, water, or acids (making it useful for coins and jewelry because it will last long in harsh conditions), yet gold is not completely inert; it reacts readily with a substance called tellurium, though that is not the only mineral is reacts with.
• Uses and applications
• Monetary exchange
• Gold coins are not only a symbol of wealth but are a good investment as the price of gold goes up.
• Gold is too soft to be used in its pure state for anything so it is combined with copper, silver, or other metals in order to harden it. Pure gold is seen as 24 karats.
• Gold standards- total value of money is equal to the amount of gold reserves for a country
• Gold standards were changed during the first world war, which cause inflation and ended all together after the second world war
• Jewelry
• Gold has been used in jewelry throughout history
• However, gold is not used in its pure state and is usually combined with copper to harden it
• Depending on the amount of copper sometimes gold can have a reddish hue to it (rose gold)
• Other times silver is used as an alloy to gold and creates white gold.
• Medicine
• In ancient times people believed that drinking gold was beneficial to health and will lengthen peoples’ lives or maybe even let them live forever.
• Gold as a metallic element is inert to all chemicals in the body and will not cure or help any illnesses; however, gold as a salt can help inflammation and are used to treat arthritis as well as other inflammatory conditions.
• Injectable gold can help treat diseases like tuberculosis
• Food and drink
• Gold foil is used on top of many desserts and is seen as a beautiful decoration to any food.
• Gold is also used in alcoholic drinks known as Goldwasser but gives no taste to the substance.
• Chemistry
• Gold is dissolved in alkaline solutions of potassium or sodium cyanide
• Sodium cyanide is used to extract gold from ores
• Gold’s oxidation forms range from -1 to +5 but Au(I) and Au(III) are most common in chemistry
• History
• Gold was used by the ancient Egyptians in tombs, vases, Funerary masks, and jewelry
• Romans developed ways to extract metal from metal ores and introduced hydraulic mining methods.
• The Aztec people regarded gold as the product of the gods
• Gold has been considered the most sought after metal for centuries
• Since gold has been used for centuries and seems to appear at the same time in many different countries; therefore no exact discovery date has been listed. The probable date of discovery would have been before written documentation.
• Gold was used to decorate palaces and pyramids 
• The metal has been used throughout history in mostly the same way that we use gold today
• Toxicity
• Pure metallic gold is non toxic and can be ingested
• Gold ion is toxic
• Gold chloride can be harmful to livers and kidneys
• Gold poisoning is rare but it can happen and cases of poisoning are usually from potassium gold cyanide
• Gold was voted allergen of the year in 2001  and the allergy to gold is mostly found in women
• Occurance
• Found in ores or in rocks of gold called nuggets
• Sometimes occurs combined with tellurium to form the minerals calaverite, krennerite, magyatite, etc.
• Gold can be found in oceans, rivers, on land in ores or in nuggets
• Production
• Gold is easily mined
• South Africa has been a source for a large quantity of mined gold
• 50% of all gold has been mined from South Africa
• China is now the largest producer of gold in the world
• Other smaller producers are the United states, Australia, Russia, and Peru
• In 2009 estimated that the amount of all the gold ever mined is equal to 165,000 tones with a value of 6.6 trillion dollars
• Isotopes
• There is only one naturally occurring isotope of gold and it is ¹⁹⁷ Au. However, gold does have thirty six radioisotopes with the only stable one being ¹⁹⁵Au with a half life of 186.1 days.
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
• Interesting facts about gold
• Gold has been recycled ever since it was first discovered; some gold in today’s jewelry is recycled from ancient artifacts and coins
• India is the largest consumer of gold
• Gold film was used in the Astronauts’ (that first landed on the moon) helmets to protect their eyes from the harsh sun.
• Some cars use gold for heat dissipation (scattering)