NAME__________________________
PERIOD_________DATE__________
REPORT FOR EXPERIMENT 2
Experiment 2 Make-Up Lab
Limiting Reactant
Background
Stoichiometry is the study of quantitative relationships that exist in the chemical
formulas and chemical reactions. We use stoichiometry to determine how much of a
substance is needed in a chemical reaction.
In class, we’ve learned to calculate how much of a chemical product that can be
made when we know the amount of reactants. In this lab, you will use this information to
determine the limiting reactant, predict how much product will be made, theoretical
yield, and compare it to the actual yield to determine your percent yield.
The reaction you will be working with is between sodium bicarbonate (baking
soda) and vinegar (5% acetic acid) that yields or produces carbon dioxide (bubbles),
water, and sodium acetate.
.
Pre-Lab Questions
1. Define all the terms in bold in the background section of this lab.
2. Write the balanced formula equation for the reaction conducted in this lab.
3. How many grams of CO2 can be produced when 0.025 g of NaHCO3 is mixed with
0.01 mol of CH3COOH?
NAME__________________________
PERIOD_________DATE__________
REPORT FOR EXPERIMENT 2
Procedure
1. The following six amounts of baking soda (sodium bicarbonate, NaHCO3) were
weighed and added to balloons:
0.18 grams, 0.35 grams, 0.52 grams, 0.70 grams, 1.00 grams, and 1.70
grams. Convert each to moles of Baking soda in table 1.
Moles of
NaHCO3
Test
Tube #
Mass of
NaHCO3
Volume of
acid, mL
1
0.18 g
10.0 mL
2
0.35 g
10.0 mL
3
0.52 g
10.0 mL
4
0.70 g
10.0 mL
5
1.00 g
10.0 mL
6
1.70 g
10.0 mL
Mass of
CH3COOH
Moles of
CH3COOH
2. 10.0 mL of vinegar (5% acetic acid, CH3COOH) was added to 6 test tubes. Fill in the
information mass and mole columns in the table above. (Note: To convert
mL of vinegar to grams multiply the volume used by the density of
vinegar: 1.01 g/mL then by 5%, the concentration of acid in the solution).
3. Each filled balloon was attached to the mouth of the test tubes and then lifted onto
one of the test tubes so that the contents of the balloon mix with the test
tube contents (as shown below).
NAME__________________________
PERIOD_________DATE__________
REPORT FOR EXPERIMENT 2
POST-LABORATORY QUESTIONS
1. Write all the possible molar ratios for the balanced equation of the reaction that
was done in this lab.
2. Calculate the theoretical yield (mass) of carbon dioxide from the moles of sodium
bicarbonate in each test-tube and complete the table below
Test
Tube #
1
2
3
4
5
6
Moles of
NaHCO3
Mole ratio of
CO2 : NaHCO3
Moles of CO2
Mass of CO2
NAME__________________________
PERIOD_________DATE__________
REPORT FOR EXPERIMENT 2
3. Calculate the theoretical yield (mass) of carbon dioxide from the moles of acetic
acid in each test-tube and complete the table below
Test Tube #
Moles of
CH3COO
H
Mole ratio of
CO2 : CH3COOH
Moles of CO2
Mass of CO2
1
2
3
4
5
6
4. For each test tube determine which reactant was in Excess and which was
limiting.
Test tube # NaHCO3
CH3COOH
1
2
3
4
5
6
NAME__________________________
PERIOD_________DATE__________
REPORT FOR EXPERIMENT 2
5.
Percentage Yield: The gas in each balloon was weighed and the results observed
are below. Complete the table to determine the percentage yield for each test tube.
Test Tube #
Actual
Mass of
CO2
0.091g
1
0.180
2
0.265
3
0.367
4
0.369
5
0.361
6
Theoretical Mass
Percentage Yield
of CO2