Donna F., Collin W. and, Alex S.
Confirmation of Solubility Chart through Formation of Metal Precipitate
Laboratory
Introduction:
Testing happens all the time. Tests are taken in class to see what you know; tests are
taken to be sure people are disease free. When testing solubility to find an unknown it is the
same concept. First it has to be established what you know then the unknown must be found
out by using previous knowledge and sending out what it looks and tests like. When things
don’t react the same then that can’t be the unknown.
Materials and Methods:
The reactants were all first mixed with sulfuric acid. First one drop was added of 1M
H2SO4 to one drop of the AgNO3 solution. Then the reactants were mixed to see the
observations. Second one drop was added of 1M H2SO4 to one drop of the Fe(NO3)3 solution.
Then those reactants were mixed to see the observations. Third one drop was added of 1M
H2SO4 to one drop of the Cu(NO3)2 solution. Then those reactants were also mixed to see the
observations. Fourth one drop was added of 1M H2SO4 to one drop of the Pb(NO3)2. Then
those reactants were also mixed to see the observations. Fifth one drop was added of 1M
H2SO4 to one drop of the Ni(NO3)2. Lastly one drop was added of 1M H2SO4 to one drop of the
Zn(NO3)2. Then those reactants were also mixed to see the observations.
Then after all the reactants were mixed with sulfuric acid then they were mixed with
sodium hydroxide. First one drop was added of 6M NaOH to one drop of AgNO 3 solution. Then
the reactants were mixed to see the observations. Then five drops were added to the same
mixture. After that it was mixed to see those observations. Second one drop was added of 6M
Donna F., Collin W. and, Alex S.
NaOH to one drop of Fe(NO3)3 solution. Then the reactants were mixed to see the observations.
Then five drops were added to the same mixture. After that it was mixed to see those
observations. Third one drop was added of 6M NaOH to one drop of Cu(NO3)2 solution. Then
the reactants were mixed to see the observations. Then five drops were added to the same
mixture. After that it was mixed to see those observations. Fourth one drop was added of 6M
NaOH to one drop of Pb(NO3)2 solution. Then the reactants were mixed to see the observations.
Then five drops were added to the same mixture. After that it was mixed to see those
observations. Fifth one drop was added of 6M NaOH to one drop of Ni(NO3)2 solution. Then the
reactants were mixed to see the observations. Then five drops were added to the same
mixture. After that it was mixed to see those observations. Lastly one drop was added of 6M
NaOH to one drop of Zn(NO3)2 solution. Then the reactants were mixed to see the observations.
Then five drops were added to the same mixture. After that it was mixed to see those
observations.
Then after all the reactants were mixed with sodium hydroxide then they were mixed
with aqueous ammonia. First one drop was added of 6M NH4OH to one drop of AgNO3 solution.
Then the reactants were mixed to see the observations. Then five drops were added to the
same mixture. After that it was mixed to see those observations. Second one drop was added of
6M NH4OH to one drop of Fe(NO3)3 solution. Then the reactants were mixed to see the
observations. Then five drops were added to the same mixture. After that it was mixed to see
those observations. Third one drop was added of 6M NH4OH to one drop of Cu(NO3)2 solution.
Then the reactants were mixed to see the observations. Then five drops were added to the
same mixture. After that it was mixed to see those observations. Fourth one drop was added of
Donna F., Collin W. and, Alex S.
6M NH4OH to one drop of Pb(NO3)2 solution. Then the reactants were mixed to see the
observations. Then five drops were added to the same mixture. After that it was mixed to see
those observations. Fifth one drop was added of 6M NH4OH to one drop of Ni(NO3)2 solution.
Then the reactants were mixed to see the observations. Then five drops were added to the
same mixture. After that it was mixed to see those observations. Lastly one drop was added of
6M NH4OH to one drop of Zn(NO3)2 solution. Then the reactants were mixed to see the
observations. Then five drops were added to the same mixture. After that it was mixed to see
those observations.
Results:
Metal
Nitrate
Color
AgNO3
Fe(NO3)3
Cu(NO3)2
Pb(NO3)2
Ni(NO3)2
Zn(NO3)2
Clear
Unknown
A
Blue
Unknown
B
Clear
Clear
Clear
Clear
Clear
H2SO4
No Rxn.
No Rxn.
Aqua
Blue
Turns
Clear
NaOH
1 Drop
Browns
Golden
NaOH
5
Drops
Ppt.
Forms
Gold Ppt.
Forms
NH4OH
1 Drop
No Rxn.
Gold
Color
Swirly
Ppt.
Forms
Ppt.
Forms
Dilutes
Color
Darker
Blue
Turns
Ppt.
Aqua
White
White
Ppt.
No Rxn.
No Rxn.
Cleat
Ppt.
Forms
Ppt.
Forms
Blue Ppt.
Forms
Blue Ppt.
Forms
Ppt.
Forms
Turns
Clear
Ppt.
Forms
Ppt. Forms
Ppt.
Forms
Clear
Turns
Light
Blue, Ppt.
Forms
Whit Ppt.
No Rxn.
White Ppt.
Forms
Dark Blue
White
Ppt.
NH4OH
5
Drops
No Rxn.
Ppt.
Forms
Ppt.
Forms
No Rxn.
Ppt.
Disappears
Ppt.
Forms
Ppt.
Donna F., Collin W. and, Alex S.
Conclusion:
During the lab chemical reactions occurred, and these obviously rearranged the molecular
makeup of certain substances. This then creates precipitates, for example:
Pb(NO3)2 + H2SO4  PbSO4 + H2(NO3). The PbSO4 is the precipitate and when formed it creates a
different color or solid texture. That is how a precipitate is formed. In the lab, many precipitates were
formed. With AgNo3, the precipitate was formed when added to NaOH since a brown color was
created. The precipitate was AgOH. With Fe(NO3)3 a precipitate was formed with both NaOH and
NH4OH. In both cases the precipitate was golden and similar in texture so it was concluded that both
precipitates were FeOH. For Cu(NO3)2 the reactions occurred with NaOH and NH4OH. Both reactions
created CuOH. This is because both created a swirly precipitate. NH4OH created a cobalt color because
NH4 reacted with NO3.Pb (NO3)2 created a precipitate in all three experiments. White precipitates were
formed with varying texture. The precipitates created were PbSO4 and PbOH. Ni(NO3)2 only reacted
with NaOH. This is because it created a small white precipitate. The Precipitate created was NiOH.
Zn(NO3)2 created a precipitate with both NaOH and NH4OH. These precipitates were gel like for the
first one and a white precipitate for the second one. The formula for the precipitates is ZnOH, but once
again, NH4 reacted with NO3 in the second test. The unknown A reacted with NaOH and NH4OH. Its
reactions matched those of copper perfectly so, it was concluded that unknown A is copper. Unknown B
had a matching turnout of lead nitrate so, it was concluded that Unknown B was lead nitrate as well. No
other reactions matched that of the unknowns, but lead and copper nitrate did perfectly. So as these
results are related back to the hypothesis it is concluded that the solubility chart does not lie. No
discrepancies were found. Many different tests were needed to find out that the solubility chart does
not lie. This is the general idea of science though. Just as in chemistry it is used in other forms of science,
such as science of theory. This is the same method that myth busters use to crack their cases.