Name ______Period ______
Chapter 4 – Chemical Dominoes
Activity 3B Outline: Grammies page 274-286
What Do You See?What Do You Think?
Ingredients:
2 1/4 cups all-purpose flour 1 teaspoon baking soda
1 teaspoon salt 1 cup (2 sticks) butter, softened
3/4 cup granulated sugar 3/4 cup packed brown sugar
1 teaspoon vanilla extract 2 large eggs
2 cups (12-oz. pkg.) chocolate chips 1 cup chopped nuts
Mix ingredients in order listed. Bake at 375OF for 9-11 minutes.
The recipe above makes 50 cookies if you follow the recipe exactly as it is written.
· If you have 4 large eggs, how many cookies could you make?
· If you have 1 cup chocolate chips, how may cookies could you make?
Investigate
Part A. Using Chemical Reactions to Tell Amounts
Complete the following activity using the bag of paper clips provided by your teacher.
1) Balance the equation written below.
_____M2 + _____C2 → _____MC3
2) Make models of the reactants and products in the equation above. Remember to include the correct number of each molecule when making your models.
3) Use your models and the extra paper clips in your bag to complete the table below.
Number of M2 Reacted / Number of C2 Reacted / Number of MC3 Produced1
2
4
6
4) Please put all of the paper clips back into the bag and return the bag to your teacher.
5) Balance the following chemical equation:
______CaCl2 (aq) + _____Na3PO4 (aq) → ______Ca3(PO4)2 (s) + _____NaCl (aq)
6) What do the coefficients in a chemical reaction indicate?
______
7) Complete the following chart using the balanced equation above.
Quantity / CaCl2 / Na3PO4 / Ca3(PO4)2 / NaClmolecules
moles
8) What is the ratio of moles of CaCl2 to moles of NaCl?
9) What is the ratio of moles of Na3PO4 to moles of CaCl2?
10) If 0.50 moles of Ca3(PO4)2 formed in the reaction, how many moles of CaCl2 are used?
11) How many moles of CaCl2 are needed to make 3.89 moles of NaCl?
Write down the steps you used to calculate the number of moles of CaCl2 you needed to make 3.89 moles of NaCl in question #11.STEP 1
STEP 2
STEP 3
STEP 4
STEP 5
STEP 6
Part B – More Practice – Mole to Mole Conversions
Please show all work when completing the problems below.
The formation of aluminum oxide from its constituent elements is represented by this equation.
______Al + ______O2 → ______Al2O3
1) Balance the equation shown above.
2) How many moles of aluminum are needed to form 3.7 mol of Al2O3?
3) How many moles of O2 are required to react with 14.8 moles of Al?
4) Calculate the number of moles of Al2O3 formed when 0.78 mol of O2 reacts with aluminum.
5) Calculate the number of moles of O2 needed to form 5.2 mol of Al2O3.
Part C – Stoichiometry of a Chemical Reaction
You will study the reaction of aluminum metal and a solution of copper (II) chloride. After you have completed the experiment, you will write a formal lab report to explain your results. Your teacher will give you more information about how to write the lab report.
1. Check your balance to make sure that it reads zero with nothing on it.
2. Measure the mass of a 50 mL beaker to the precision of your balance. Record the mass in the data table below.
3. Measure out approximately 0.5 g of aluminum metal into the empty beaker. Record the mass of the aluminum metal and beaker.
4. Measure the mass of a 150 mL beaker. Record this information in the data table provided.
5. Place approximately 3.00 g of copper (II) chloride in the 150 mL beaker. Record the exact mass of the copper (II) chloride.
6. Add 25 mL of distilled water to the beaker containing the copper (II) chloride. Stir the solution until all of the copper (II) chloride has dissolved.
7. Add the aluminum metal to the beaker containing the copper (II) chloride solution.
8. Record your observations of the chemical reaction that occurs when you added the aluminum to the copper (II) chloride solution.
9. Using a pencil, label the edge of a piece of filter paper with your group name.
10. Record the mass of the filter paper in your data table.
11. Set up a filtration system as demonstrated by your teacher.
12. When the reaction has stopped, pour the contents of the 150 mL beaker onto a piece of filter paper. Rinse the beaker a few times with distilled water to be sure that all of the contents of the beaker are transferred.
13. Carefully remove the filter from the funnel and place it on a watch glass. Allow the filter paper to dry overnight.
14. When the filter paper is dry, measure the mass of the filter paper and its contents.
15. Dispose the filter paper and its content as directed by your teacher.
Finding the mass of the aluminum metalMass of empty 50 mL beaker
Mass of beaker and aluminum metal
Mass of aluminum metal
Finding the mass of copper (II) chloride
Mass of empty 150 mL beaker
Mass of beaker and copper (II) chloride
Mass of copper (II) chloride
Finding the mass of the product
Mass of dry filter paper
Mass of filter paper with product after drying
Mass of product material
Observations of Reaction:
Day 1
Day 2
Part D – Conversions Involving Grams, Moles, and Equations
In the lab you did today, you placed aluminum metal in a solution of copper (II) chloride. The equation below shows the chemical equation for the reaction you observed.
______Al + _____ CuCl2 → _____ AlCl3 + ______Cu
1) Balance the equation written above.
2) Calculate the molar mass of each substance involved in this reaction.
Aluminum / Copper (II) chloride / Aluminum chloride / Copper3) Determine the amount of reactants used and the amount of products formed given the following mole and gram values.
Exp. / Quantity / Al / CuCl2 / AlCl3 / Cu1 / moles / 2.0 moles / 3.0 moles / 2.0 moles / 3.0 moles
grams / 54 g / 403 g / 267 g / 190 g
2 / moles / 4.0 moles
grams / 108 g / 534 g / 380 g
3 / moles
grams / 26.7 g
3) You used 0.5 g of aluminum in this reaction. How many grams of copper should you make in the reaction?
STEP 2
STEP 3
STEP 4
4) You used 3.00 g of copper (II) chloride in the reaction. How many grams of aluminum reacted with the copper (II) chloride?
5) You do another experiment using 2.5 g of aluminum. How many grams of aluminum chloride do you make in the reaction?
6) You use 15.1 g of copper (II) chloride in your reaction. How many grams of copper do you make?
7) You make 25.6 g of copper in a reaction. How many grams of aluminum did you use in the reaction?
Part E – More Practice
1. Balance the chemical reaction:
_____ Mg + ______FeCl3 → ______Fe + ______MgCl2
2. If you start the reaction with 5.0 g of Mg, how many grams of Fe would you make?
3. If you start the reaction with 14.5 g of iron (III) chloride, how many grams of Mg would you need for the reaction?
4. If you start the reaction with 125 g of iron (III) chloride, how many grams of magnesium chloride would you make?
5. If you start the reaction with 150 g FeCl3, how many grams of Mg would you need for the reaction?
Part F – Limiting Reagents
Complete the following activity using the bag of paper clips provided by your teacher.
1. Join together pairs of paper clips of the same type (metal with metal, vinyl coated with vinyl coated) to form models representing 10 diatomic molecules of each reactant.
2. Place these molecules in the plastic bag.
3. Without looking, choose 15 molecules from the plastic bag.
4. Line up the M2 and C2 molecules in two adjacent vertical rows.
5. List the number of each type of reactant molecule that was drawn from the bag.
6. Pair up reactant molecules in the proper ratio as shown in the equation below: M2 + 3C2 → 2MC3. Make the molecules “react” by taking them apart and forming two molecules of the products.
5. Continue making M2 and C2 react in a 1:3 ratio until you run out of one of the reactants.
6. Record the number of MC3 molecules you were able to form.
7. Record the number of M2 and C2 molecules left over.
Number of M2 molecules before reactionNumber of C2 molecules before reaction
Number of MC3 molecules formed
Number of M2 molecules remaining
Number of C2 molecules remaining
8. Which reactant molecule ran out first? This reactant is called the limiting reagent.
9. Relate the idea of limiting reagent to a recipe you might use to cook your favorite food.