Homework #20

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. Recycling: Cans. 

19. a. Soil, water, plants, animals. 

      b. Petroleum, copper, natural gas, coal. 

20. a. reusing. 

      b. recycling.
      c. reusing. 

21. Both glass from a light bulb and paper from a newspaper can be recycled. In fact, 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.

Retrieving Copper Lab

Livia, Sydney, Jimmy Neutron

Retrieving Copper Lab:

Abstract: The purpose of the part one experiment was to extract the Cu from the Copper chloride sample. We preweighed both of the filter paper to 1.02 grams, and waited a day or so to record the weight of the filter paper with the experimented copper samples on it. During the lab, we struggled with correctly measuring the hydrochloric acid, because we poured too much excess. Also, we got set back because we overheated the beaker, which made it more time consuming. The final results of our first copper sample was .66 and for the second, it was .48.

Procedure:

Part I: Separating Copper(II) Oxide (CuO) from the Sample:

The first step in the procedure was to weigh our copper sample. The weight was 1.4 grams. Now that the sample is weighed, we have to distribute 50mL of HCl to the beaker containing the copper oxide mixture. After the mL of HCl was added to our copper chloride mixture, we gently and carefully heated the mixture to 40 degrees Celsius. When we obtained the correct temperature, we maintained that temperature, stirring was required with a glass rod. When we successfully achieved the correct temperature, we removed it from the hot plate. The unreacted copper from there formed a precipitate at the bottom of the beaker. From that point, the copper liquid was filtered into another, empty, 100mL beaker.

Once the first step of the filtration process is done, we washed the solid copper in the first beaker with distilled water. We decanted the liquid in the second beaker, and added it to the liquid we just collected. The mass of the filter paper was 1.02. The filter paper is currently drying overnight.

Part II: Converting Copper (II) Chloride (CuCl2) to Copper (Cu):

The final step in this lab is converting the dissolved copper (ii) chloride into copper metal. Our first step in the second part of the procedure was to cover the top of a beaker with a watch glass. For each gram of copper powder that we started with, we add one gram of zinc. We have noticed that the zinc dissolved into the calcium chloride. From there the zinc turned black, to white, to red. Once the reaction subsided, we added 10mL of HCl to the beaker, and from there we decanted as much of the liquid possible.

The copper from there was carefully washed several times with distilled water. It was added to a piece of filter paper that weighed 0.01 grams, and left it to dry overnight.  

Questions:

1.

a. The evidence that led me to believe the reaction was incomplete was because it took a serious amount of time.

b. By adding more hydrochloric acid.

2.
a. When we first got the copper the weight was 1.4 grams but after we weighted it again it weights .16 grams for the converted one. For the unconverted one we started at 1.4 grams and when we re weighted it, the weight was 1.13 grams.
b. For the converted one the percent was 11.4 percent of the copper that reacted, for the unconverted one  81% of the copper reacted. 

3.

a. Cu2 + Zn2+ à Cu + Zn2-

b.

i. Zn

ii. Cu

iii. distilled water

iiii. HCl

4. The zinc turned black, now the water is turning white, then eventually turning red.

5.

a. Zinc

b. Onto the filter paper.

Homework #19

2CAS #13-17


13. a. 6 moles
      b. 5 moles
      c. 5 moles

14. a. 1 mole

      b. 621 g 
      c. 28 g 
      d. 415 g

15. The percent of the oxygen atoms is 67%, because oxygen's molar mass is 32 and carbon's molar mass is 12 in this molecule. Therefore, the percent oxygen by mass 32g/44g x 100%, or 73%. 

16. 

a. 

molar masses: Ag -216g and S -32g
87% silver by mass
b.
molar masses: Al -54g and O -48g
53% aluminum by mass
c. 
molar masses: Ca-40g; C-12g; O-48g
40% calcium by mass

17. 

a. 68%

b. 10%

c. 6.8%

Homework #18

2CAS #1-12


1. The law of conservation of matter is that matter cannot be created nor destroyed. 


2. Scientific law summarizes what has been learned by careful observation of nature.

3. Those expressions can be interpreted as confusing because molecules can be converted and decomposed by chemical processes, but atoms are forever, and are not "used up" or "thrown away."


4. 
a. Not balanced.
Reactant side: Sn, 1; H, 1; F, 1
Product side: Sn, 1; H, 2; F; 2
b. Not balanced. 
Reactant side: Si, 1; O, 2; C, 1
Product side: Si, 1; O, 1; C, 2
c. Balanced. 
Reactant side: Al, 1; O, 3; H, 6; Cl, 3
Product side: Al, 1; O, 3; H, 6; Cl, 3

5. a. 3
    b. 2 
    c. 1 


6. See on paper.


7. a. 1 Ca3(PO4)2 + 3 H2SO4 --> 2 H3PO4 + 3 CaSO4
    b. 2 C8H18 + 25 O2 --> 16 CO2 + 18 H2O

8. 

a. Yes. 

Reactant side: Na, 2; S, 1; O, 4; K, 2; Cl, 1
Product side: Na, 2; S, 1; O, 4; K, 2; Cl, 1
b. No. Although the subscripts remained the same, the coefficients have been altered. 
c. 1 Na2SO4 + 2 KCl --> 2 NaCl + 1 K2SO4

9. ?

10. 

a. 32g
b. 48g
c. 100g
d. 58g
e. 180g

11. Although copper and sodium have different masses, volumes, and densities, the weight of each atom per mole remains the same. 

12. 

a. 1 
b. 0.5 
c. 0.1 
d. .3 

Metal Report: Lead

Metal Report: Lead (Pb)

The metal I chose to report on was lead. Lead is an extremely toxic element, and a really heavy metal. Lead has 82 protons, 82 electrons, and an atomic mass of 207; this indicates that when neutralized, lead has 125 neutrons. As an ion, lead has a positive 2 charge. Lead also has four stable isotopes, 204Pb, 206Pb, 207Pb, and 208Pb; all except for lead-204 can be found in the end products of the radioactive decay of uranium and thorium. Lead is very high in toxicity and if one is diagnosed with lead poisoning, it can be fatal. Since 1978, lead’s usage has been significantly reduced. Lead can be found in pottery, electrical storage batteries, cooking appliances, pesticides, and paints. It is still used to paint bridges and other steel structures with paint made with red lead (Pb3O4), a compound of lead and oxygen. Because of its relatively low reactivity (not quite as low as gold or silver), it protects these steel structures from corrosion. This however, is not a threat to the general public, but if used in items that come in contact with humans, will cause lead poisoning that can result in death. Leads symbol (Pb) comes from the Latin name plumbum, like plumber and plumbing, because water pipes in ancient Rome were made of lead. Lead was also used in the US in the paint used on homes built before 1978. Many children would become very sick, especially toddlers, from coming in contact with the flaking paint. Lead-based paint is no longer used in homes; alternatives like water-based paints are used instead. Since lead is so heavy, especially oxidized, it is used to protect from radiation from x-rays and to make weights, such as fishing weights. Since there are fewer regulations in countries like China, lead is still commonly used to produce items. In fact, toys made with lead paint imported from China have affected the US. Children were made sick and even faced death from simply playing with Barbies, action figures, and building kits. It is important to recognize that lead is not only found in less regulated countries, but all over the world. In fact, car batteries are usually made out of significant amounts of lead! Surprisingly enough, the chief producers of lead, or where it is chiefly mined, is, from greatest to least, The US, China, Germany, the United Kingdom, and Japan. Lead is highly abundant, quite unreactive, and found in the lithosphere of earth. Lead is extracted from these ores using pyrometallurgy, the treatment of the metals and their ores with heat, as in a blast furnace-- the common reducing agents being Carbon (coke) and carbon monoxide.

Homework #17

2SBS #9-18


9. Active metals are more reactive than less active metals. Because of this, more active metals are more likely to combine and form compounds with other elements, where as less active metals tend to remain separate. 


10. Silver would have been the easiest to process because of its lack of reactivity. Since silver remains separate from other metals and elements, it would be quite easy to process. 


11. Since most metals are more reactive than metals like silver, gold, and platinum, their reactivities tend to make them combine with other elements and form compounds, or minerals. 


12. a. A reaction between calcium metal with chromium(III) chloride would more likely occur. Calcium metal is more reactive than chromium metal; therefore, putting calcium metal in chromium chloride would create a reaction, where as putting chromium metal in calcium chloride would not form any reaction. 


13 . b. Since zinc is much more reactive than silver, which is barely reactive, putting the metal zinc into a silver solution would cause a reaction; a reaction occurs between a more reactive metal and a less reactive solution. 


14. a. Since iron is more reactive than lead, stirring a solution of lead (II) nitrate with an iron spoon would cause a reaction, and the iron spoon would most likely begin to dissolve. 
      b. Pb^2+(aq) + Fe(s) ---> Pb(s) + Fe^2+(aq)

15. Oxidation is the apparent loss of one or more electrons that causes a metal to become a cation/aqueous solution. Reduction is the apparent gain of one or more electrons that causes a cation/aqueous solution to balance its electrical charge and become a metal. 

16. a. Au^3+ + 3e^- ---> Au

      b. V ---> V^4+ + 4e^-
      c. Cu+ ---> Cu^2+ + 1e^-

17. a. reduction.

      b. oxidation.
      c. reduction. 

18. a. Zn^2+ has been oxidized. Zn loses two electrons to become a cation/aqueous solution, Zn^2+. 

      b. Ni has been reduced. Ni^2+ gains two electrons to essentially rebalance its charge and become a metal/solid as Ni.
      c. The reducing agent in this reaction is Zn.


19. ?


20. a. Al + Cr^3+ ---> Al^3+ + Cr
b. Mn^2+ + Mg ---> Mn + Mg^2+

21. I don't know

22. a. Electrometallurgy.
b. Pyrometallurgy or find the metal uncombined.

Extra Credit Report (4)

Dark Matter: Material Answers

• Dark matter is a theory composed of particles that cannot interact with the electromagnetic force. 
• Unable to interact with light, but do interact gravitationally. 
• The gravitational pull of dark matter stops galaxies from flying apart as they rotate. 
• It is said that there is 5x as much dark matter than regular matter. 
• Both of these types of matter tend to cluster together, because they are both highly affected by gravity. 
• It is said that the universe was originally filled with threads of dark matter, and regular matter formed around them. 
• This created galaxies.
• Dr. Dietrich and his colleagues detected the part of a thread that runs between two groups of galaxies; the light and dark matter. 
• they did so by looking through the distorted effect of the thread's gravity. 
• They concluded the threads shape and its mass, which is about 60 trillion times the mass of the sun. 
• This article is important to me because it is very interesting to know that there is enough dark matter 60 trillion times larger than the mass of the sun.