The aim of this experiment is to convert copper metal through a series of intermediate copper compounds back into copper metal. By weighing the copper at the beginning and at the end of the experiment the percentage yield can be determined.
Method:
The experiment was carried out as outlined in the practical manual.
Results:
Table: showing masses:
Mass copper wire
0.2510
Mass crucible
28.9257
Mass watch glass
19.6213
Mass watch glass + copper
19.7890
Mass copper product
0.1677
Calculations:
Percentage yield:
Discussion and conclusion:
The percentage yield of copper was calculated to be reasons for such a low yield could be from a few factors such as not all the copper setteling to …show more content…
Some precipitate may have been lost when the supernatant liquid was decanted which can result in a yield of less than 100%. Yield may have also been lost when transferring the sample from the beaker into the crucible.
6. This occurs when reactions are not allowed to finish resulting in some of the unwanted precipitate remaining behind. The unwanted precipitate will not precipitate in the subsequent reactions. If the final copper sample is not dry before you weight it could weigh more than 100%
7. Copper sample is brown/red in colour. The copper provided was a shiny brassie colour. This is because the copper provided was in form of a wire. It had undergone further processing. And my final copper sample may have picked up impurities along the way, which made it darker in colour.
8. Acetone is a flammable ketone. If exposed to temperatures greater than its flash point it may explode or cause flash fire.
9. The yield would be more than a 100%, the calculated yield would be incorrect and not a true reflection of actual yield.
10. Because you are adding concentrated nitric acid to a piece of copper. A reaction takes place and gas (NO2 ) is released. [5-10 makes =1 ]
11. Moles of copper wire: