9. Active metals can easily react with another substance and combine making them commonly hard to separate and must be processed by electrometallurgy and pyrometallurgy.
10. Silver would be the easiest to process, and right behind silver would be copper and zinc; however, magnesium would be very difficult to process. Silver and copper and zinc would be easiest to process they are the least reactive metals out of the 4 we were given and would not easily combine with other ions.
11. Most metals exist in nature as minerals rather than as pure metallic elements because the majority of metals are quite reactive and can combine easily to become minerals.
12. a) Calcium with Chromium is more likely to react because Calcium has a higher reactivity than Chromium does, and will therefore cause a reaction unlike the reverse which would cause no reaction because less reactive metals cannot react with more reactive ions.
13. b) 2Ag+(aq) + Zn(s)----> 2Ag(s) +Zn2+(aq) - this reaction is more likely to occur because ZInc is more reactive than silver; therefore, the ion must be the silver, which is less reactive. Once the reaction occurs the oxidation and reduction of Zinc and Silver occur readily.
14. a) Lead nitrate is less reactive than iron metal (spoon) so when the spoon touched the lead a reaction would definitely occur. b) Pb2+(aq) + Fe(s)----> Pb(s) + Fe2+(aq)
15. Oxidation is the loss of electrons to become an ion while reduction is the gaining of electrons to neutralize into a metal.
16. a) Au+(aq) + 1e- ----> Au(s)
b) V(s) + 4e+ ----> V4+(aq)
c) Cu+ + 1e+ ----> Cu2+
17. a) Reduction
b) Oxidation
c) Reduction
18. a) Zinc has been oxidized because it has gone from being a solid metal to losing two electrons in order to become a solution of Zn2+
b) Nickel has been reduced because it has gone from being a solution with an ionic positive charge of 2 and gained two electrons to become a solid of Nickel metal.
c) The reducing agent in this reaction is Zinc.
19. a) Potassium has been oxidized because it has gone from 2 atoms of metal Potassium to 2 atoms of positively charged ionic solution of potassium
b) Mercury has been reduced in this equation because it has gone from being a positively charged ion to a solid neutral metal.
c) The oxidizing agent is the Mercury because it allows the Potassium to change from a metal to an ion by making it lose two ions.
20. a) Al + Cr3+ ----> Al3+ + Cr
b) Mn2+ + Mg ----> Mn + Mg2+
21. a) Electrometallurgy is a process by which electrical current is used to supply electrons to metal ions, thus reducing them.
b) Pyrometallurgy is a method where metals and their ores are treated with heat in a blast furnace where Carbon and Carbon monoxide are common reducing agents. They provide electrons.
c) Hydrometallurgy is treating ores and other metal-containing materials with reactants ina water solution.
22. a) Electrometallurgy
b) No process is needed, usually found uncombined in a pure metal form.
Sunday, July 10, 2011
Friday, July 8, 2011
Relative Reactivities of Metals Lab
Questions: #1-8, page 143:
1. Which metal reacted with the most solutions?
Although both magnesium and zinc showed reactions with copper nitrate and silver nitrate, magnesium’s reaction with copper nitrate was more apparent than zinc’s.
2. Which metal reacted with the fewest solutions?
Copper reacted with the fewest solutions.
3. Assuming that you did not test silver metal, with which solutions (if any) would you expect silver metal to react? Explain your answer, citing evidence from your data and observations.
Although we didn’t test silver due to its high price, going into the experiment we were aware that silver is a very unreactive metal (the reason why it is used in jewelry). Silver would not have reacted with any of the solutions.
4. List the metals (including silver) in order, placing the most reactive metal first (the one reacting with the most solutions) and the least reactive metal last (the one reacting with the fewest solutions).
Magnesium, zinc, copper, silver.
5. Refer to your “metal activity series” list from Question 4. Write a brief explanation of why the outside surface of a penny is made of copper instead of zinc.
Although silver is the least reactive, less than copper, it is too expensive to use on the outside of a penny. Since copper is also an unreactive metal, it is used on the outside of pennies since it will not corrode over time or melt under standard temperatures due to its high melting point.
6. A) Which of the four metals mentioned in this investigation might be an even better choice than copper for the outside surface of a penny? What observational evidence supports your conclusion?
Silver. Silver is the least reactive out of all of the metals.
B) Why do you think that the particular metal that you identified in Question 6a is not used as the outside surface of a penny?
As previously stated, silver is way too expensive to use to make pennies.
7. Given your new knowledge about the relative chemical activities of these four metals,
A) which metal is most likely to be found in an uncombined, or “free,” (metallic) state in nature?
Silver and copper is most likely to be found in an uncombined, or “free” metallic state in nature because they are the least reactive and seldom combine with other substances. This is why copper is used on the surface of pennies and silver (and gold) are used to make jewelry.
B) which metal is least likely to be found chemically uncombined with other elements?
Since magnesium was the most reactive out of the four metals we tested, it is least likely to be found chemically uncombined with other substances in nature. Magnesium combines with other substances very easily due to its high reactivity.
8. Reconsider your experimental design for this investigation:
A) Would it have been possible to eliminate one or more of the metal-solution combinations and still obtain all the information needed to create chemical activity ratings for the four metals?
Yes, it would have been possible to eliminate two of the metal solution combinations and still obtain all of the information needed to create chemical activity ratings for the four metals.
B) If so, which combination or combinations could have been eliminated? Why?
Due to silver’s high price, we eliminated it from our experiment. Since we knew that silver is an unreactive metal, removing it from the test was not a problem. Since we know that zinc is a reactive metal, the reason it is used as the core and not the surface of the penny, we could have removed it from our experiment as well.
1. Which metal reacted with the most solutions?
Although both magnesium and zinc showed reactions with copper nitrate and silver nitrate, magnesium’s reaction with copper nitrate was more apparent than zinc’s.
2. Which metal reacted with the fewest solutions?
Copper reacted with the fewest solutions.
3. Assuming that you did not test silver metal, with which solutions (if any) would you expect silver metal to react? Explain your answer, citing evidence from your data and observations.
Although we didn’t test silver due to its high price, going into the experiment we were aware that silver is a very unreactive metal (the reason why it is used in jewelry). Silver would not have reacted with any of the solutions.
4. List the metals (including silver) in order, placing the most reactive metal first (the one reacting with the most solutions) and the least reactive metal last (the one reacting with the fewest solutions).
Magnesium, zinc, copper, silver.
5. Refer to your “metal activity series” list from Question 4. Write a brief explanation of why the outside surface of a penny is made of copper instead of zinc.
Although silver is the least reactive, less than copper, it is too expensive to use on the outside of a penny. Since copper is also an unreactive metal, it is used on the outside of pennies since it will not corrode over time or melt under standard temperatures due to its high melting point.
6. A) Which of the four metals mentioned in this investigation might be an even better choice than copper for the outside surface of a penny? What observational evidence supports your conclusion?
Silver. Silver is the least reactive out of all of the metals.
B) Why do you think that the particular metal that you identified in Question 6a is not used as the outside surface of a penny?
As previously stated, silver is way too expensive to use to make pennies.
7. Given your new knowledge about the relative chemical activities of these four metals,
A) which metal is most likely to be found in an uncombined, or “free,” (metallic) state in nature?
Silver and copper is most likely to be found in an uncombined, or “free” metallic state in nature because they are the least reactive and seldom combine with other substances. This is why copper is used on the surface of pennies and silver (and gold) are used to make jewelry.
B) which metal is least likely to be found chemically uncombined with other elements?
Since magnesium was the most reactive out of the four metals we tested, it is least likely to be found chemically uncombined with other substances in nature. Magnesium combines with other substances very easily due to its high reactivity.
8. Reconsider your experimental design for this investigation:
A) Would it have been possible to eliminate one or more of the metal-solution combinations and still obtain all the information needed to create chemical activity ratings for the four metals?
Yes, it would have been possible to eliminate two of the metal solution combinations and still obtain all of the information needed to create chemical activity ratings for the four metals.
B) If so, which combination or combinations could have been eliminated? Why?
Due to silver’s high price, we eliminated it from our experiment. Since we knew that silver is an unreactive metal, removing it from the test was not a problem. Since we know that zinc is a reactive metal, the reason it is used as the core and not the surface of the penny, we could have removed it from our experiment as well.
Thursday, July 7, 2011
2SAS #26-34 and 2SBS #1-8
26. Metallic substances are more likely to lose electrons because they tend to be more reactive and be positive ions.
27. They are chemically inert.
28. a) cation b) cation c) anion d) cation e) anion f) cation g) anion h) anion
29. a) Copper metal and copper ions. I chose this option because the other option compares two substances that chemically contain different things while copper metal is just a certain copper ion that still has the same chemical make up without changing any thing about the substance other than the amount of electrons which frequently fluctuates.
30. 156+254/2= 205 picometers
31. a)oxidation, food coloring
b) reaction between lithium and water, boiling manually by heat source
c) reaction of HCl to Copper causing gas bubbles, H2o at its boiling point becoming a gas
32. a) Bromine b) Silicon
33. The Data is similar because along with temperature or reaction to an acid the amount of metals will go up so the reactiveness is similar as well as the way we constructed the data for the fish kill was by mass of metals and pH while Mendeleev also used atomic mass. He also had to make assumptions just like our class did.
34.
vs. 
_________________________________________________________
1. Atmosphere- Nitrogen, Oxygen, Argon Hydrosphere- Sulfer, Calcium, Magnesium Lithosphere- Magnesium, Iron, Aluminum
2. Crust, Mantle, and Core.
3. a) Mexico b) Japan c) China
4. China
5. Ores are naturally occurring rocks or mineral that can be mined and from which it is profitable to extract a metal, whereas minerals are the most important continents of the mixture of components found in the ores.
6. Quantity, percent of metal, type of mining and process needed for extraction, distance between mine and metal-refining facilities, supply and demand, environmental impact.
7. The value of gold because it is so unreactive and hardly gets ruined and the possibility of new gold forming because of nutrients being revitalized.
8. Useful Ore refers to the minerals in the ore.
The Difference Engine: Hold the carcinogens
http://www.economist.com/blogs/babbage/2011/07/healthy-eating
With grilling being so popular among the American population, awareness of the dangers posed by carcinogens in meats has become a pertinent subject. Since 1970, we have known leaving beef, pork, fowl, and fish cooking at high temperatures causes heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). These forms of cancer can be produced at a relatively low temperature of 3000F, when our grills can reach up to 7000F, or more, within minutes. At such high temperatures, meat becomes burnt, and unhealthy for consumption quickly. HCA’s are formed when amino acids and sugars react at a high temperature to create an energy boost that later may become cancerous. One of the cancer causing boosts is called harmane and causes shaking of the arms, head, jaw, and voice and can be found in 20 times more people than Parkinson’s disease. PAH’s, on the other hand, can be found when fuels such as oil, coal, tar, and wood are burned. They are even usually removed from vehicle exhaust because they are so harmful. In food, they are found when the fat and juices from the meat drip onto the red hot coals or splash plates, causing a flame to form. When this flame makes contact with the meat, the PHA’s in the flame go onto the meat. After eating the meat, HCA’s and PAH’s alter the DNA in body cells, increasing susceptibility to cancer. When experimenting with rodents, scientists found those that were fed with HCA and PAH in their food developed tumors; however, the amount of HCA and PAH the rodents were given was disproportional to the amount the average human can consume. But even without the rodent information, people who ate medium to well-done beef were 3 times more likely to suffer from stomach cancer than those who prefer rare or medium-rare beef. Also men who consumed 3 grams of well-done meat had a 40% higher chance of getting prostate cancer. Even though World Cancer Research Fund and the American Institute for Cancer Research issued a release in 2007 asking people to cut down on red meats and smoked food in general, they failed to mention PAH’s or HCA’s and the later damage caused by cancer. The statement these institutes made did not make the American population completely aware of the cancerous high risks and really should have. Some helpful tips for avoiding consumption of HCA’s and PAH’s to the best of our ability is eating protein packed food such as tofu and marinating meats for at least 6 hours before grilling would decrease levels of HCA’s and PAH’s dramatically as well as only using the ends of grills which remain at 2200F. We need to be more careful with our lives even at the cost of our appetites.
With grilling being so popular among the American population, awareness of the dangers posed by carcinogens in meats has become a pertinent subject. Since 1970, we have known leaving beef, pork, fowl, and fish cooking at high temperatures causes heterocyclic amines (HCAs) and polycyclic aromatic hydrocarbons (PAHs). These forms of cancer can be produced at a relatively low temperature of 3000F, when our grills can reach up to 7000F, or more, within minutes. At such high temperatures, meat becomes burnt, and unhealthy for consumption quickly. HCA’s are formed when amino acids and sugars react at a high temperature to create an energy boost that later may become cancerous. One of the cancer causing boosts is called harmane and causes shaking of the arms, head, jaw, and voice and can be found in 20 times more people than Parkinson’s disease. PAH’s, on the other hand, can be found when fuels such as oil, coal, tar, and wood are burned. They are even usually removed from vehicle exhaust because they are so harmful. In food, they are found when the fat and juices from the meat drip onto the red hot coals or splash plates, causing a flame to form. When this flame makes contact with the meat, the PHA’s in the flame go onto the meat. After eating the meat, HCA’s and PAH’s alter the DNA in body cells, increasing susceptibility to cancer. When experimenting with rodents, scientists found those that were fed with HCA and PAH in their food developed tumors; however, the amount of HCA and PAH the rodents were given was disproportional to the amount the average human can consume. But even without the rodent information, people who ate medium to well-done beef were 3 times more likely to suffer from stomach cancer than those who prefer rare or medium-rare beef. Also men who consumed 3 grams of well-done meat had a 40% higher chance of getting prostate cancer. Even though World Cancer Research Fund and the American Institute for Cancer Research issued a release in 2007 asking people to cut down on red meats and smoked food in general, they failed to mention PAH’s or HCA’s and the later damage caused by cancer. The statement these institutes made did not make the American population completely aware of the cancerous high risks and really should have. Some helpful tips for avoiding consumption of HCA’s and PAH’s to the best of our ability is eating protein packed food such as tofu and marinating meats for at least 6 hours before grilling would decrease levels of HCA’s and PAH’s dramatically as well as only using the ends of grills which remain at 2200F. We need to be more careful with our lives even at the cost of our appetites.
The Acids: Converting Copper Lab
Notes: Procedure:
• Copper powder before the heating is a fine brick-red powder substance
• After the two minutes being on the hot plate, the substance was charcoal and stiff with a slightly purple hue
• Then it was removed from the hot plate and broken up as much as possible with a spatula into a not as fine powder
- Then we placed the crucible back on the hot plate for 10 more minutes with the top ajar to let some oxygen in
• Every two minutes we removed the crucible from the hot plate and broke up the solid with a spatula as previously done
• After the first 2 minutes, it remained a powdery substance with more solid particles
- Instead of having a purplish hue it had a charcoal color
• After the next two minutes the substance remained the same
• After the next two minutes the substance remained the same
• Then we removed the crucible from the hot plate, placed it on the base of the ring-stand, and allowed its contents to cool to room temperature
Questions: Page 140:
1. Answers
a. Describe changes you observed as you heated the copper.
i. We observed color change and the formation of solid particles within the heated crucible. In the first stages of heating, the copper became charcoal in color with a slightly purple hue, and by the end of the heating cycle, the copper was completely charcoal in color.
b. Did the copper atoms remain in the crucible? Explain, using evidence from your observations.
i. Yes the copper did remain inside the crucible but there were slight powder stains on the sides of the crucible that changed color along with the rest of the powder.
2. Answers
a. Were the changes you observed physical changes or chemical changes?
i. As we observed, the copper oxidized; therefore, the changes were chemical changes.
b. What observational evidence leads you to that conclusion?
i. It is a chemical reaction because burning, or combustion, involves chemical reactions between the copper and the oxygen.
3. Answers
a. How did the mass of the crucible contents change after you heated the copper?
i. The mass of the contents did not change at all, they were exactly the same before and after heating
b. Explain why the mass of the crucible contents change in that manner.
i. Although we recognized that the mass of the crucible content should have increased after oxidization, it remained the same. This may be due to crushing the powder too fine, or because of not enough copper particles oxidizing.
Aggregated Data:
Average gain: 0.06g
Median gain: 0.06g
Wednesday, July 6, 2011
2SAS #13-25
13. a) periods b) group or family
14. Sodium-Na and Potassium-K
15. a) the far right column b) they are very unreactive c) they are chemically inert
16. a) MgF2 b) GaP3
17. about 68 degrees celsius
18. Higher
19.
20. a) protons-4 , neutrons-5 , electrons-4 b) protons-7, neutrons-7, electrons-7 c) protons-10, neutrons-10, electrons-10
21. The student is incorrect because a +2 ion indicates the loss of 2 electrons making the atom positively charged.
22. a) Carbon-12, Carbon-13, Calcium-41, Platinum-195, Uranium-238
b) Carbon
23. No it is not, we would also need the atom's ionic charge, melting point, boiling point, state of being (gas, liquid, solid), and the element's proton and neutron count.
24. An electron's mass is so much smaller than a proton and neutron it is not included in the atomic weight because it is so minuscule.
25.
Tuesday, July 5, 2011
2SAS #1-12 pg. 130
1. a) physical property b) chemical property c) chemical property d) physical property
2. a) physical property b) physical property c) physical property d) chemical property
3. a) chemical property b) chemical property c) chemical property d) physical property
4. a) chemical property b) chemical property c) chemical property d) chemical property
5. a) A cut apple left out in the air turns brown because of the exposure to oxygen which creates a chemical reaction, displaying a chemical property b) Flashlight batteries lose their "charge" after extended use because they can no longer be used to facilitate use and have created a chemical property c) Dry cleaning removes oils from clothing because it is a nonpolar substance combining with oil a nonpolar substance creating a chemical reaction and making it a chemical property d) Italian salad dressing separates over time because it is a suspension and is not homogeneously mixed so chemically will separate displaying another chemical property
6. a) When making chocolate chip cookies one must get all the ingredients, mix them together to form a dough, let them set in the refrigerator, put them on a baking sheet, put them in the oven, let them cool.
b) Mixing the ingredients is a chemical change because it is creating a reaction with all the ingredients to form a new substance; the dough. Letting the dough set in the refrigerator is physical property because the dough become firmer. Putting them in a shape on the baking sheet is a physical property because the dough stays the same in a different shape. Baking them in the oven is a chemical property because the substance didn't change but it cooked because the heat allowed the cookies to get harder.
7. a) metal b) nonmetal c) nonmetal d) metal
8. a) metal b) metalloid c) nonmetal d) metal
9. Boron- B, Silicon-Si
10. a) Because Iodine is a nonmetal, it should shatter into pieces and be brittle b) Zirconium would bend and be maleable because it is a metal c) phosphorus would shatter and be brittle because it is a nonmetal d) nickel would bend and be maleable because it is a metal
11. Nonmetals are non electrically conductive and they also shatter easily into small pieces and cannot bend to fit around small areas and into smaller wires.
12. Metals are good for coins because faces such as Abraham Lincoln's on the penny can be printed on to them easily because they bend, metals also can last a long time, and they also are cost effective while still being good quality.
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