Mole Ratio Lab - October 28 Class

Today in class, we completed the Mole Ratio Lab. Our objective of the lab was to find out the ratio of moles of iron, to moles of copper.

The Pre-Lab consisted of:
1) 2Fe + 3CuCl2 -> 3Cu 2FeCl3.
2) The ratio of moles of copper produced to moles of iron consumed is 3:2

The materials we used were:
Apparatus:
Beakers (250 mL)
Wash bottle
Stirring Rod
Crucible tongs
Centigram balance
drying oven
safety glasses
lab apron
plastic gloves
sand paper or emery cloth
face shield
Reagents:
copper (II) chloride
2 iron nails (approx. 5 cm)
1 M hydrochloric acid
distilled water

Our procedure:
1. Find the mass of 250mL beaker. Record the mass to the nearest hundredth of a decimal (g)
2. Add 8g of copper (II) chloride crystals to the beaker. Find and record the mass.
3. Add 50mL of distilled water to the beaker. To dissolve the crystals, swirl the beaker around.
4. Clean and dry 2 nails. Use sand paper if needed. Then, find and record the mass of the nails.
5. Put the nails into the solution and leave them there for 20 min. Observe the formation of copper and some of the iron that will be used up in the beaker.
6. Pick up the nails one by one using the tongs. Before removing the nails from the beaker, use distilled water to rinse off any remaining copper. Use a stirring rod to scrape any excess copper if needed. Let the nails dry on a paper towel.
7. Find and record the mass of the nails after they are completely dry.
8. (Decant- pour off only the liquid from a container that is holding both liquid and solid.)
Decant the liquid from the solid by putting the liquid into another beaker.
9. After decanting, rinse the solid with 25mL of distilled water. Decant again. Repeat this step 4 more times.
10. Wash the solid with 25mL of 1M hydrochloric acid. Decant again (twice). Then clean the solid with 25mL of distilled water.
11. Place the oven in a drying oven to dry.
12. Let the copper dry, then find and record the mass of the beaker + copper.
13. Make sure to clean up your lab and wash your hands properly.

Our observations:
Mass of empty dry beaker = 159.34g
Mass of beaker + copper (II) chloride = 167.34g
Mass of 2 iron nails = 5.45g
Mass of 2 iron nails (after) = 4.95g / 5.0g
Mass of beaker with copper (after) = 160.72g

We discovered that 0.5g of iron was used in the reaction and 4.95 g of copper was produced.
Our final ratio was 1.5:1 and we had a percent error of 56%. This is because we could have spilled some of the liquids and there was too much liquid in the copper and it didn't dry out fully.