PERFORMANCE ASSIGNMENT                                 Lab Nine

Moles of Iron and Copper and Calculating Error


The mole is a convienient unit for analyzing chemical reactions and the mass of a mole is the mass in grams of the molecular formula. In this reaction iron nails will be exposed to copper II chloride from which the moles can be determined. As the lab is done this time, you will calculate the percent error after finding the theoretical and actual yields.


Objectives

1. Determine the number of moles of copper produced in the reation
2. Determine the number of moles of iron used in the reaction
3. Determine the ratio of moles of iron to moles of copper
4. Calculate the theoretical and actual yields.

Procedure

1. Find the mass of a clean and empty cup, record
2. Add about 8 g of copper II chloride to the cup, find the mass and record
3. Add 50 ml of water to the cup and swirl the cup around to dissolve all the crystals
4. Obtain two clean and dry nails. If they are not clean, use sandpaper to shine, find and record the mass
5. Place the nails into the copper II chloride solution for 20 min.
6. Use tong to pick up nails one at a time. Scrape and wash off any copper back into the beaker. Set aside the nails and dry.
7. Find the mass of the dry nails and record.
8. Decant the liquid from the cup. Add 25 ml of water and wash, decant again.
9. Rinse all the copper into a small beaker decant and place the beaker in the drying oven.
10. After the copper has dried find the mass of the beaker plus the copper and record.

Data

mass of cup

  

mass of cup and CuCl2

  

mass of CuCl2

  

mass of nails before

  

mass of nails after

  

mass of Fe

  

mass of beaker

  

mass of beaker and Cu

  

mass of Cu

  

Calculations

1. Find the number of moles of the following:

Moles of iron used:



Moles of CuCl2 used:



Moles of Cu produced:



2. Using the moles of iron used, calculate the theoretical yield for copper.



3. Find the percent yield by dividing the actual yield by the theoretical yield.



4. Calculate error by subtracting the percent yield from 100

Back to Syllabus

Back to Laboratories

Scoring