Arianna S. Abundo

Chemistry IBS1-D

Mrs. Zimmerman

November 12, 2007

Data Collection

Table 1.  Table showing initial mass, final mass and qualitative observation of copper electrodes.

Table 2.  Table showing current of copper electrodes in 600 second intervals.

Note:  As both copper electrodes were placed in a single beaker of copper sulfate, the data obtained for the current is the same for both electrodes.  Thus, the “Current” column in Table 2 represents the current of both copper electrodes.

Table 3.  Table showing voltage used during the experiment.

Data Processing

Moles:

Number of moles

Electrode 2, which lost 0.53 grams after being placed in copper sulfate, contains approximately 0.00834 moles of copper.

Uncertainty of moles

Uncertainty of mass  =  Uncertainty of initial mass + Uncertainty of final mass

Uncertainty of mass  =  0.005 g + 0.005 g

Uncertainty of mass  =  0.01 g

Percent uncertainty of mass  =

Percent uncertainty of mass  =

Percent uncertainty of mass  ≈  1.89%

The percent uncertainty for the number of moles is approximately 1.89%.  Thus, the number of moles is approximately 0.00834 ±1.89%.

Current:

Average charge =  Average current  x  time

After 10 minutes

Average current  =

Average current  =  0.9 A

Percent uncertainty of average current  =

Percent uncertainty of average current  ≈  11.1%

The percent uncertainty for the average current is approximately 11.1%.  Thus, the average current after 10 minutes is 0.9 A ±11.1%.

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#### Here's what a teacher thought of this essay

This is a 4 star piece of work with excellent calculations and clearly laid out steps to calculate Avogadro's number. The layout of the investigation needs to be improved with suggestions for an aim, introduction, scientific information, prediction, method and risk assessment. If these improvements are done this would be a 5 star piece of work.