Stoichiometry Lab – Iron Nail

Purpose:To use stoichiometry to calculate the percent error of copper produced in the reaction.

Safety: Goggles must be worn during all lab procedures

Materials:

1 250-mL beaker

1 50-mL beaker

Tongs

Microspatula

Plastic wash bottle

Glass stirring rod

35-mL CuCl2

1 iron nail

Steel wool

Filter paper

Funnel

Procedure:

DAY 1

  1. Write a name on your filter paper IN PENCIL. Find the mass and record it in your data table.
  2. Add 35-mL of copper(II) chloride to the 250-mL beaker.
  3. Clean an iron nail with steel wool to remove rust.
  4. Find the mass of the nail & record it in your data table as Iron Nail (before reaction).
  5. CAREFULLY slide the nail into the copper(II) chloride solution using tongs & let the beaker stand undisturbed for 20 minutes.

***While you wait you can do the additional problems #5 & #6

  1. Remove the nail with tongs. Holdit over the beaker and wash/scrape off the product that formed on the nail.
  2. Allow the nail to dry on a paper towel.
  3. Carefully pour excess solution into the 50-mL beaker DO NOT allow ANY copper to go with the solution. If there is no copper in the solution, pour it down the sink. Rinse the solid product left in the beaker with your wash bottle. Again, poor the solution into the other beaker and down the sink. Continue until the solid product is clean with no green solution left. Place your filter in the funnel, then use the wash bottle to move the product from the beaker into the filter paper to dry.

DAY 2

  1. Clean off any residue and weigh the nail and record it in your data table as Iron nail (after).
  2. Return the nail to the teacher.
  3. Weigh the dried filter paper & productand record it in your data table.
  4. Dump the dry product and filter paper into the trash can.

DATA TABLE 1
Items / Mass
Empty filter paper with name
Iron nail (before reaction)
Iron nail (after reaction)
Filter paper with product (after)
DATA TABLE 2 Observations
Step / Observations (at least 2 things)
6

***BCE: 2Fe + 3CuCl22FeCl3 + 3Cu

Analysis (show ALL work for calculations)

  1. Determine the mass of iron lost by the nails. (Nail before – Nail after)
  2. Determine the mass Copper produced in the lab. (Filter paper with product-empty filter paper)
  3. Calculate the theoretical amount of copper from the iron lost by your nail. (Start with your mass of iron lost from #1, use stoichiometry to find the grams of copper produced)
  4. Calculate the % error. % error = (measured value Cu–theoretical value)÷theoretical valuex100

*** “Measured” is your answer to #2 & “Theoretical” is your answer to #3

Additional Stoichiometry Problems

  1. If you started with 3.54 g of iron, how many grams of copper should be produced?

(Usestoichiometry!!)

  1. If you start with 35.0g of Copper(II) chloride, how many grams of Iron(III) chloride should be produced? (Use stoichiometry!!)