Can somone check for tenses? My chem teacher takes off marks for incorrect tenses. :hmm:
Creating an Activity Series of Metals
Purpose:
To determine an activity series for a number of metals
Materials:
32 test tubes
Test tube rack
5 pieces of copper
5 pieces of magnesium
5 pieces of Tin
6 pieces of Zinc
5 pieces of Iron
6 pieces of Steel
Diluted Hydrochloric Acid
Water
Copper (II) Sulfate (CuSO4)
Iron (II) Chloride (FeCl2)
Magnesium Nitrate (Mg(NO3) 2)
Tin (II) Chloride (SnCl2)
Procedure:
1) Six pieces of Zinc were distributed and placed in their own test tubes
2) Diluted Hydrochloric Acid, Water, cooper (II) Sulfate, Irion (II) Chloride, Magnesium Nitrate and Tin (II) Chloride were poured into 6 different test tubes containing the Zinc metals. Enough was poured so that the solution covered the metal.
3) Reactions were observed and recorded.
4) Reactions of other metal-metal solution reactions were recorded from the blackboard.
5) The metals and the solutions were disposed of into a chemical waste jug.
Observations: See Table1
Analysis:
Cu(s) + HCl(aq) → no reaction
Cu(s) + H2O(aq) → no reaction
Cu(s) + FeCl2(aq) → no reaction
Cu (s)+ Mg(NO3) 2(aq) → no reaction
Cu (s)+ SnCl2(aq) → no reaction
Mg(s) + 2HCl(aq) → H2(g) + MgCl2(aq)
Mg(s) + H2O(aq) → no reaction
Mg(s) + CuSO4(aq) → Cu(s) + MgSO4(aq)
Mg(s) + FeCl2(aq) → Fe(s) + MgCl2(aq)
Mg(s) + SnCl2(aq) → Sn(s) + MgCl2(aq)
Sn(s) + HCl(aq) → no reaction
Sn(s) + H2O(aq) → no reaction
Sn(s) + CuSO4(aq) → Cu(s) + SnSO4(aq)
Sn(s) + FeCl2(aq) → no reaction
Sn(s) + Mg(NO3) 2(aq) → no reaction
Zn(s) + 2HCl(aq) → + H2(g) + ZnCl2(aq)
Zn(s) + H2O(aq) → no reaction
Zn(s) + CuSO4(aq) → Cu(s) + ZnSO4(aq)
Zn(s) + FeCl2(aq) → no reaction
Zn(s) + Mg(NO3) 2(aq) → no reaction
Zn(s) + SnCl2(aq) → Sn(s) + ZnCl2(aq)
Fe(s) + 2HCl(aq) → H2(g) + FeCl2(aq)
Fe(s) + H2O(aq) → no reaction
Fe(s) + CuSO4(aq) → Cu(s) + FeSO4(aq)
Fe(s) + Mg(NO3) 2(aq) → no reaction
Fe(s) + SnCl2(aq) → Sn(s) + FeCl2(aq)
Activity Series obtained from observations:
Magnesium Most reactive
Iron
Zinc
Hydrogen
Tin
Copper Least reactive
An actual activity series is as follows (1):
Cesium Most Reactive
Lithium
Rubidium
Potassium
Barium
Strontium
Calcium
Sodium
Magnesium
Aluminum
Manganese
Zinc
Chromium
Iron
Cadmium
Cobalt
Tin
Lead
HYDROGEN
Copper
Silver
Mercury
Platinum
Gold Least Reactive
Discussion:
According to the observations, Magnesium was the most reactive metal because it reacted with all of the solutions except for water (which reacted with none of the metals) and no metals reacted with the Magnesium Nitrate solution. The second most reactive metal was Iron because it reacted with everything except for water and the Magnesium solution, because magnesium was more reactive, hence it could not dispel the Magnesium. The third most reactive was Zinc which could not dispel Iron or Magnesium in their respective solutions. Hydrogen, while not one of the metals tested, was next element on the activity series. It was in two of the solutions, Hydrochloric Acid (HCl) and water (H2O). While water reacted with no metals, HCl reacted with Magnesium, Zinc and Iron; everything above itself on the activity series. Neither HCl nor water reacted with Tin and Copper that indicated that hydrogen is more reactive than both of these metals. The second least reactive metal was Tin because it reacted with one metal solution: the copper solution. It was not reactive enough to dispel any other metals from their solutions. Finally the least reactive metal was Copper because it reacted with no solutions while all of the other metals reacted with the Copper (II) Nitrate solution.
In the actual activity series, Zinc is more reactive than Iron and Tin is more reactive than Hydrogen. This could be because the Zinc was covered with a layer of oxide that prevented it from reacting with the Iron solution. Due to the fact that Zinc did not react with the Iron solution, the conclusion of Iron is more reactive than Zinc was made. A possible reason why Zinc appeared to be more reactive than Hydrogen could be that the hydrocholoric acid was too diluted. The low concentration of HCl reacted in very slowly with Tin and could have given the appearance that it was not reacting at all. It is also very possible that a layer of oxide was on the Tin. Due to the fact that Tin did not react with both HCl and water it was concluded that it was more reactive than Hydrogen. Another factor that should be considered while observing reactions is the amount of time that is required for a reaction to occur. For example, all substances would eventually react with water. If a substance was placed in water for a long period of time signs of reaction will be visible to the naked eyes. A final reason why some reactions were not observed between metals and the solutions was because of the temperature of the reactants. Some substances only react with each at high temperatures.(2, 4) This is due to the fact that these substances requires more energy to initiate a reaction (ie. Endothermic reactions) and at cold temperature they do not have sufficient energy to form new bonds.
During the lab, observations were made with Water and Hydrochloric Acids. While HCl reacted with most of the metals water did not react with any. Water does not react with any of the metals at room temperature because it is a covalent bond (the ΔEN between O-H is 1.24) (3) none of the elements has enough energy to “break the bond” between hydrogen and oxygen. The natural dissociation of water molecules (at 25°C) into H+ and OH- is at the ration of 1 x 10-14. (5) This means that there are very few OH- molecules that other atoms can react with. This is why water seemed like it does not react with any of the metals. For two molecules to collide they must “bump” into each other and since there are very few dissociated OH- molecules then it is less likely that a metal atom will bump into it. In HCl however, the H+ and Cl- dissociates almost completely (100%) all the time. (6) This creates a lot of opportunities for reactions to happen and this is why most of the metals tested reacted with HCl and not Water.
Conclusion:
The purpose of the lab was met, a activity series was determined from the results of the lab. The reactivity series that was determined was:
Magnesium Most reactive
Iron
Zinc
Hydrogen
Tin
Copper Least reactive
In comparison to actual activity series, Zinc should have been more reactive than Iron and Tin should have been more reactive than Hydrogen.
Bibliography
1) Class notes
2)
GCSE CHEMISTRY - The Reactivity of Metals with Water - GCSE SCIENCE.
3) Mustoe, F. Michael P. Jansen, Ted Doram, John Ivanco, Christina Clancy Anita Ghazariansteja. Chemistry 11. Toronto: McGraw-Hill Ryerson. 2001
4)
http://educ.queensu.ca/~science/main/conce...c02/c02cdd4.htm
5)
http://wine1.sb.fsu.edu/chm1046/notes/Acid...H2O/DissH2O.htm
6)
http://itl.chem.ufl.edu/2045_s00/lectures/lec_z1.html
--Mandy