Name: Jared Lill
Date Performed: 9/1/15
Class: Chemistry 1211L, 565
Lab Report 2: Determining Avogadro’s numberMaterials
The materials we used consisted of Lab quest, a balance, a vernier constant current system, a beaker, a copper strip, zinc strip, and sodium sulfate. Our objective was to measure the amount of copper deposited after the electrification process.
A beaker was filled with approximately 250 ml of sodium sulfate. The vernier constant current system (will be referred to as VCCS) was connected to lab quest. The negative wire from the VCCS was connected to the zinc and the positive wire was connected to the copper. The VCCS was turned until 300 amps were showing on the Lab Quest and then turned it off. We set the duration for 400 seconds and at .2 samples/second. The copper was then weighed at 3.974g. WE started the experiment by putting the copper connected to the VCCS into the sodium sulfate for 400 seconds. When the time ended the copper was then reweighed at 3.921g. We took the difference which was 5.3E-2. We then proceeded to calculate the number of copper atoms in a mole.
We took the mean of the amount of amps used in the process which came to .300 coul/sec and multiplied this by the 400 seconds. This gave us 120 coul. We divided this number by 1.6E-19coul. This came out to 7.5E20e-. We took this number and divided it by 2 to get the number of atoms, 3.75E20 atoms of copper. The atoms of copper were then divided by our difference in grams of copper lost. This came out to 7.075E21 atoms Cu/grams Cu. This was then divided by the atomic weight to get it into moles. The final outcome was 4.496E23 atoms/mol.
We needed to find the percent error of our calculations and Avogadro’s number. We took our number (Ex. Value) subtracted it by Avogadro’s number (true value) and then divided it by Avogadro’s number (true value).This gave us a -25% error
The same procedure it trial one was used for trial two….
Name: Jared Lill