Conclusion and Evaluation:
Aspect 1 Based on the interpreted data of group “A”, the empirical formula of aluminum chloride did not stay the same. The expected empirical formula was. In group “A” the empirical formulas are as followed…
Laurie & Jordan
Rica, Victoria & Stephanie
Vince & Josh
Jane & Kaityln
So, as a group, we all had a different outcome of the empirical formula but the percent composition of water is the same for all. 11.2% for hydrogen and 88.8% for oxygen as shown in table #7.3.
A random error would be the measurement of the hydrate crystal. A scoopula was used to measure 3g. Also another one would be the electronic balance having an uncertainty of ï¿½0.001g. A systematic error would be heating the evaporating dish through a wire mesh instead of a clay triangle.
You notice that the theoretical yield and experimental yield values are shown in a pie graph. Both of the pie graphs are the exact same as both percentages are 11.2% and 88.8%. In these pie graphs, neither trends nor patterns apply.
Aspect 2 The procedural weaknesses are stated above. For example the measurement of the hydrate crystal would’ve affected the lab. There wasn’t an accurate measurement so that could’ve affected the weight of the final product or the reaction of the product. Another weakness was that the evaporating dish was being heated through a wire mesh instead of a clay triangle. The wire mesh had a white coating on it, so therefore the evaporating dish was being heated indirectly and the wire mesh would absorb the heat itself. This would affect the heating process of the evaporating dish and the substance inside of it. There were a few assumptions made in this particular lab. They are as followed…
Possible effect on the result
All of the moisture was removed from the evaporating dish
If all the moisture wasn’t removed, then an accurate and precise reaction isn’t obtained.
The aluminum chloride was pure
If impure aluminum chloride was used then other products could have formed
The only substance reacting with the aluminum chloride was itself as a hydrate form
This could have had other reactions which therefore will affect the products formed.
All of the aluminum chloride hydrate evaporated
Could possibly effect the measurement of the weight
3g of aluminum chloride was added to the evaporating dish
Obviously if there were less or more than 3g added, it will affect the outcome result
The quality of the data was fair. The precision and accuracy of the aluminum was absent since it was measured by a scoopula and estimation. Although, the same balance was used to weigh all the masses, therefore the accuracy of those measurements were present with the exception of the uncertaintyï¿½0.001g.
Aspect 3 If this lab were to be redone, I think that everything should stay the same besides 2 factors which are the use of wire mesh and the measurement of the hydrate crystal. If we were to use a clay triangle instead of the wire mesh, the evaporating dish would have been directly heated instead of being indirectly heated. This would remove the systematic error. A better precision and accuracy would be obtained if we actually used a measuring device. For example, a measuring spoon would’ve been more accurate than the scoopula. Using the same balance for all masses would obtain greater control of variables and reduce the random error.