Part B of the lab called for green
chemistry; green chemistry manages waste to lower the quantity of waste through
changing how chemicals can be disposed of for a move towards a green world. After
part A was conducted, part B had us take the hydrochloric acid and zinc
reaction to test the pH level to see if we could dump it in the “sedimentation
station”. After adding NaOH, the pH monitor was used to see if the reaction was
neutralized. If the pH meter reached 8-9 then it was appropriate to dump into
the provided station.
There were sources of errors that arose
in this experiment. One source could’ve come from the large difference in
diameter, length and mass in sample 10 from the overall class data. This could be
an example of reading something incorrectly or not zeroing out the balance
which could drastically change the data needed to determine the standards. Another
error could’ve occurred if all nails reacted to hydrochloric acid at the same
time. It would be difficult to keep a consistent time for all nails; time
management is important, because it maintains the accuracy we want for every
reaction. If one nail was left longer than another, that nail could be dissolving
not only the zinc, but possibly the iron as well. This could cause the mass,
length, diameter and overall appearance to change from what the data calls for.
In our lab, each nail was timed independently, but it is unknown if all groups
maintained the same procedure.
purpose of this lab was to determine the quality of the zinc coating of the individual
nails. Through this, the galvanized nails can be compared to two industry
standards: the higher standard being 1 oz. of coating per square foot^3 and the
lower standard being 0.28 oz./ft^2. By using 6M hydrochloric acid on the nails,
the zinc coating can be removed then the mass lost (g) can be calculated. In
the 5 nails that were used in my lab, I found that the average was BLANK g/mm2
and the overall class average was BLANK g/mm2.