Help I have to write chemical equation and I do not know how?
Now the Question that I have to answer is "Write a chemical equation that represents the reaction with with the other 4 solutions (as mentioned above) which of these reactions were spontanious?
Please help. If you need more information then ask and I will do my best to provide it.
Answer:
I'm going to assume that they all form copper salts with a +2 oxidation state, which is probably an ok assumption.
You're doing 4 single displacement reactions here, where the metals in the nitrate salts get displaced by the copper. Not all of them will happen spontaneously because of the activity series of metals.
1. Cu + Zn(NO3)2 --> Zn + Cu(NO3)2, will not occur spont.
2. Cu + Fe(NO3)2 --> Fe + Cu(NO3)2, will not occur spont.
3. Ni(NO3)2 + Cu --> Ni + Cu(NO3)2, will occur spont.
4. AgNO3 + Cu --> Ag + Cu(NO3)2, will occur spont.
So when you did the lab, you should have seen changes for the 3rd and 4th reactions, and you should have seen a blue, or blue green liquid form because the copper nitrate will dissolve and be blue-green. You also should have seen metal form, silver metal or zinc metal depending. Zinc metal looks like silver or gray color, and silver metal you've probably seen before.
You are given a metal Cuº and cations of metals M+a
your only conclusion has to be that:
M+a + ae- --> Mº * 2
and
Cuº --> Cu+2 + 2e- * a
add
2M+a + aCuº --> 2Mº + aCu+2
To figure out whether the reaction will be spontaneous look at this table:
ref: http://www.csudh.edu/oliver/chemdata/dat...
If the potential for the reduction of the metal in question (read directly from the table) - (oxidation of copper = -0.34V) is greater than zero:
potential reduction + 0.34V > 0 then the reaction is spontaneous
Take Zn+2
Ered = - 0.76
Eox = -0.34
Ecell = -0.76 - (-0.34) = -0.42 NOT-spontaneous
example reaction:
Zn(NO3)2(aq) + Cu(s) <--- Zn(s) + Cu(NO3)2(aq)
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