Limiting Reagent Lab

advertisement
Limiting Reagent Lab
Purpose- To determine the limiting reagent of a reaction with Copper (II) chloride and
Aluminum.
Materials· Aluminum Foil
· Copper (II) Chloride Dihydrate (CuCl2 • 2 H2O)
· 250-mL Beaker
· 400-mL Beaker
· Centigram Balance
· Spatula or Scoopula
· Distilled Water
· 1.0 M HCl
· Plastic Weighing Dish
Procedure1. Mass the 250-mL beaker
2. Mass about (not exactly) 7.50 gram sample of CuCl2 • 2 H2O in a plastic weighing
dish.
3. Mass close to (not exactly) a 0.50 gram sample of Aluminum foil in a plastic
weighing dish.
4. Place the 7.50 gram sample of CuCl2 • 2 H2O into a 250-mL beaker. Make
sure to get ALL of the CuCl2 • 2 H2O.
5. Add 100-mL of distilled water to the beaker and CuCl2. Mix the CuCl2 into the
distilled water with a glass stirring rod.
6. Roll the Aluminum foil into a loose ball and place it into the CuCl2 solution. Mix gently
to avoid breaking up the ball and submerge the aluminum.
Record your observations on your data sheet.
7. Once the reaction is complete, decant the liquid into the 400-mL beaker.
Rinse the solid with distilled water and decant the liquid. Make sure to not
lose any of the solid. Rinse the solid two more times.
8. Add 20-mL of 1.0 M HCl to the solid for the final rinse. Decant the liquid, and
rinse one more time with distilled water.
9. Place your beaker into the drying oven for massing on the next day. Make
sure you and your lab partner’s name appear on the beaker.
10. Place decanted material in the hood in the large waste container.
Name: _______________________
Date: _________________
Limiting Reagent Analysis Worksheet
DataMass of empty 100-mL beaker ______________________________________
Mass of CuCl2•2H2OUsed ___________________________________________
Mass of Aluminum foil Used _________________________________________
Mass of 250-mL beaker with solid (after drying) __________________________
Observations of Chemical Reaction-
Analysis1. How do you know a chemical reaction is taking place?
2. What type of reaction is taking place?
3. Write the balanced equation for the chemical reaction of CuCl2 and Al. Make
sure to include states of matter.
4. Determine how many grams of CuCl2 your really have present. (Realize we
started with CuCl2 • 2 H2O and not just CuCl2 )
5. Which of the reactants is the limiting reagent? Prove your answer through
calculations.
6. Without performing any calculations, could you determine which of the
following reactants the limiting reagent is? Explain your answer.
7. What is the theoretical yield you should obtain from this reaction of CuCl2 and
Al? Show your work!
8. What is the actual yield of the solid product?
9. What is the percent yield for the reaction?
10.Give three sources of error which would affect the data of the experiment.
Make sure to include explanations as to how each source of error.
Download