Balanced Reactions Lab
The purpose of this lab was to use empirical evidence to determine the type of
chemical change and be able to write these changes as balanced reactions. We found
that 9 out of 16 reactions yielded precipitates and 1 had a color change (Cu(NO3)2 x
KI). To set up this experiment, we combined different solutions in a well plate. 3
drops of Ca(NO3)2, Cu(NO3)2, Ni(NO3)2, and Zn(NO3)2 were put into wells A1 to
A4, B1 to B4, C1 to C4, and D1 to D4 respectively. Next, 3 drops of KI, KOH,
Na2C2O4, and Na2SO4 were placed in wells A1 through D1, A2 D2, A3 D3, and
A4 D4 respectively. We then let the solutions sit awhile before recording our
observations. In wells A2, A3, A4, B2, B3, C2, C3, D2, and D3, precipitates formed.
Also, in well B1 had a color change but no precipitate.... Show more content on
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The reason why Na2SO4 only reacts with Ca(NO3)2 is because when sulfate
combines with calcium (or Ag, Sr, Ba, Pb), it becomes insoluble. In the other
reactions, copper, nickel, and zinc were all soluble when combined with sulfate.
Also, no precipitate formed when mixed with KI because both elements in the
molecule are soluble when combined with other elements, except for Ag, Pb, and
Hg when combined with a halide. This lab shows that some elements and ions are
soluble while others are not and that there are some exceptions to the rule. During
our first try, my group had few errors. In our B4 well, a precipitation reaction
occurred when in actuality, there should not have been