Observation Report Estimating the duration Redox Reaction

I. Destination
Knowing the relationship influence the color change before and after reaction with use traditional course of the reaction with evidence of the potential price of the cell.

II. Materials and tools
• 5 pieces of test tubes
• 1 piece of test tube rack
• Table cell potential price
• 1 piece of metal Mg, Zn and Pb
• 2 pieces of metal Cu
• A solution of HCl
• CuSO4 solution
• solution of ZnSO4
• A solution of Pb (NO3) 2


III. How it Works
1. Prepare 5 pieces of test tubes.
2. Wash clean test tube.
3. Putting all five pieces to the shelf test tube reaction tabunng
4. Incorporating approximately 5ml (or to taste, can be seen from the reaction):
• HCl solution into the first tube
• CuSO4 solution into the second and third tube
• ZnSO4 solution into the fourth tube
• A solution of Pb (NO3) 2 into the fifth tube
5. Setting up the pieces of Mg, Zn, Pb and Cu, then enter:
• Mg metal into the first tube. Observe and record what has happened.
• Zn metal into the second tube. Observe and record the color change logan and solution before and after the reaction.
• Pb metal into the third tube. Observe and record the color change logan and solution before and after the reaction.
• Cu metal tube into the fourth. Observe and record the color change logan and solution before and after the reaction.
• Cu metal tube into the fifth. Observe and record the color change logan and solution before and after the reaction.
See the following picture:

Mg Cu Zn Pb Cu



HCl CuSO4 CuSO4 ZnSO4 Pb (NO3) 2

IV. Observation
1. Reaction of Mg metal with HCl
Color before Color after
Mg Gray black White long gone
HCl Bening Stay clear clear clear

2. Reaction of metal pendesakan
Tube to a metallic-color Observations Observations color of the solution
before after before after
2 carat Color Gray, long devastated Blue Light blue nodes for long clear
3 Silver Somewhat clear black Blue Light blue long clear
4 Yellow gold Yellow gold Bening Bening lucid lucid
5 Yellow gold Yellow gold Bening Bening lucid lucid

V. Conclusion
The color change before and after the reaction takes place to determine whether or not a reaction.
• If the color of the reaction solution before and after the change, meaning the reaction can take place.
• If the color of the solution before and after the reaction remains, meaning the reaction can not take place.
This can be evidenced by the price table cell potential, namely:
• If the price of a reaction after the cell potential is calculated, the price is positive means that the reaction can take place.
• If the price of a reaction after the cell potential is calculated, hargany negative reaction means that it can not take place.

VI. Answer Questions
1. Among the five trials that I observe,
• The reaction can take place is the group 1, 2, 3.
Ø HCl (aq) + Mg (s) + H (s) + MgCl (aq)
Ø CuSO4 (aq) + Zn (S) Cu 2 + (s) + ZnSO4 (aq)
Ø CuSO4 (aq) + Pb (s) Cu2 + (s) + PbSO4 (aq)
• The reaction can not take place is the group 4 and 5.
Ø ZnSO4 (aq) + Cu 2 + (s)
Ø Pb (NO3) 2 + Cu 2 + (s)
2. a. Potential price of each cell:
• HCl (aq) + Mg (s)
H + Eo = Eo - Eo Mg2 +
= 0.00 - (-2.375) = +2.375

• CuSO4 (aq) + Zn (S)
Cu2 + Eo = Eo - Eo Zn2 +
= +0.34 - (-0.763) = +1.103

• CuSO4 (aq) + Pb (s)
Cu2 + Eo = Eo - Eo Pb2 +
= +0.34 - (-0.126) = + 0.466

• ZnSO4 (aq) + Cu (s)
Zn2 + Eo = Eo - Eo Cu2 +
= -0.763 - (+0.34) = -1.103

• Pb (NO3) 2 + Cu (s)
Pb2 + Eo = Eo - Eo Cu2 +
= -0.126 - (+0.34) = -0.466
b. There is a relationship between cell potential price of the course of a redox reaction.
• If the potential price of cells positive (> 0), meaning the reaction can take place.
• If the potential price of cells positive (> 0), meaning the reaction can take place.

Redox Reactions and Electrochemistry

- Definition of corrosion
Corrosion is
v redox reaction between a metal with a variety of substances in the environment that produces a compound - a compound that is not desired.
v oxidation reaction of a metal which forms rust with Fe2O3.xH2O formula.

- Factors - factors that support berlangsugnya corrosion:
v Oxygen
v Water
v Acidity
v Contact with other metals
v Lead
v Air Humidity

- Prevention of corrosion:
v Changing iron into stainless steel (stainless steel).
v Painting.
Paint can avoid contact with air and water. Paint containing lead and zinc (zinc) will be better, because they protect the metal against corrosion.
v Pelumuran with oil and grease.
This method is applied to a variety of tools and machinery. Oil and grease to prevent contact with water.
v dressing with plastic.
Plastics can prevent contact with water and air.
v Tin plating (coating with tin)
Cans tyerbuat packaging of iron coated with tin by electrolysis. Tin metal that resists rust classified. However, the tin coating protects the iron during the coating was intact (without paint). If the tin layer is broken, such as scratches, then lead it to encourage or accelerate the corrosion of iron. It happens because the reduction potential is more negative than the tin iron (Fe E0 = -0.44 V, E0sn2 + I sn = - 0.14 V). Therefore, iron coated with tin to form an electrochemical cell with iron as the anode. Thus, pushing tin corrosion of iron. But this is precisely what is expected, so the tin - tin cans quickly destroyed.
v Galvanization (with a zinc coating).
In contrast to tin, zinc can protect iron from corrosion even if the lining is intact. This happens because of a protection mechanism called the cathode. Because iron reduction potential more positive than zinc, iron mak contact with zinc to form an electrochemical cell with iron as the cathode. With that case, unprotected iron and zinc which is oxidized.
v Cromium Plating (with a chromium coating).
Iron or steel can also be coated with chromium to a glossy protective coating member, for example for automobile bumpers. Cromium Plating is also done by electrolysis. Just like zinc, chromium can be member protection and chromium layer was damaged.
v Sacrificial Protection (sacrificial anode).
Magnesium is a metal that is much more active (meaning more easily corroded) dariapada iron. If metallic magnesium is contacted with iron, magnesium then it will not rust, but iron. This method is used to protect steel pipes are planted in soil or marine hull. Periodically, magnesium rod must be replaced.
v Modification of the environment
Because oxygen and air moisture is a major factor in the corrosion process, it reduces oxygen levels and lowers the humidity can slow the rusting process. For example, the humidity in the warehouse can be reduced by cooling the warehouse using the AC.
v Modification of Iron
When menbentuk iron alloys with elements - certain elements of iron would be more resistant to corrosion. Steel (alloys of iron) containing 11-12% chromium and low in carbon, so-called stainless steel, stainless steel and is often used in industry, for chemicals, and in the household.
v Cathodic Protection
v If ferrous metal associated with zinc, iron would be difficult to experience corrosion. This is because zinc is more easily oxidized than iron (zinc reduction potential E0zn2 + I zn = - 0.76 V) is more negative than the reduction potential of iron (Fe E0Fe2 + I = - 0.44 V). Zinc will react with oxygen and water in an environment containing carbon dioxide and form zinc carbonate compound. Zinc carbonate formed itself serve to protect zinc from corrosion. How to protect metal like this is called the way Cathodic Protection (cathode protector). In addition to zinc (Zn), metal magnesium (Mg) which includes an alkaline earth is widely used for this purpose.

- Given: metals iron, zinc, aluminum, and chrome
a) Metals are the most rapidly oxidized
v aluminum (Al E0Al3 + I = - 1.66 V)
v Zinc (E0zn2 + I zn = - 0.76 V)
v Chromium (Cr E0Cr3 + I = - 0.74 V)
v Iron (Fe E0Fe2 + I = - 0.44 V)
- Tins is a tin-coated steel, while the roof is zinc coated steel
a) Zinc (E0zn2 + I zn = - 0.76 V)
Tin (E0sn2 + I sn = - 0.14 V)
So the cans are more resistant to rust than the roof, because the roof is less than E0 E0 cans.
b) Canned easier than rusty tin roof because if the layer is broken, such as peeling, then lead it to encourage or accelerate the corrosion of iron. It happens because the reduction potential of iron is more negativ than tin (E0 = -0.44 V Fe, E0sn2 + I sn = - 0.14 V). Therefore, iron coated with tin to form an electrochemical cell with iron as the anode. Thus, pushing tin corrosion of iron.