Objective
1.to observe a vareity of chemical reactions
2.to interpt and explain observations with balanced chemical equations
3.to classify each reactions as one of the four main types
Reaction 1
Using crucible tongs, hold a 6cm length of bare copper wire in the hottest part of flame for few minutes.
The flame turns green when burnning the copper, and the color of copper changes.
2 Cu + O2 ---> 2 Cu2O
Reaction 2
Place the iron nail in a test tube and add copper sulfate solution so that one half of the nail is covered.
The solution turns green and copper is formed.
Fe + CuSO4 ---> Cu + FeSO4
Reaction 3
Heat the test tube which contains some solid copper sulfate pentahydrate.
There is smoke seen, and pentahydrate turens to white, then green, then green.
CuSO4·5H2O ---> CuSO4 + 5H2O
Reaction 4
Use a medicine dropper to add 2 or 3 drops of water to the test tube from reaction 4.
And the color of the pentahydrate turns to blue again.
CuSO4 + 5H2O ---> CuSO4·5H2O
Reaction 5
Fill a test tube one quarter full with CaCl2 solution, then fill another test tube with solution Na2CO3. Pour the CaCl2 soultion into the test tube contatining NaCO3 solution.
The white precipitate is formed during the reaction.
Na2CO3 + CaCl2 ---> CaCO3 + 2 NaCl
Reaction 6
Place a piece of mossy zinc in the test tube, then HCl acid solution into the test tube until the mossy zinc is completely covered.
There is bubble seena, the amount of zinc is decreased.
Zn + 2 HCl ---> H2 + ZnCl2
Reaction 7
Half fill a test tube with hydrogen penoxide, then add a small amount of manganese oxide.
There are bubble seen, the reaction is speeding up.
2 H2O2 ----> 2 H2O + O2
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