Chemical Reactions: Actual and Theoretical Yields
Dr. Walt Volland, Copyright 1999-2013, all rights reserved revised July 19, 2013
In this experiment you will examine the reaction between baking soda and vinegar. The baking soda is sodium bicarbonate, NaHCO3. Vinegar is a 5% solution of acetic acid, HC2H3O2, in water. The products of the reaction are water, H2O, carbon dioxide, CO2, and sodium acetate, NaC2H3O2. The reaction you are working with is shown here. You will collect the carbon dioxide gas and figure the mols of gas produced from the ideal gas equation, PV = nRT, and your data. |
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You will measure the amount of baking soda used. You will collect and measure the quantity of carbon dioxide formed. You will be able to calculate the % yield for the reaction by comparing the actual mols of carbon dioxide collected with the predicted mols from the mol ratio in the equation. This reaction can also be expressed using a net ionic equation. The reaction is really between the hydrogen ion, H+, of the acid and the bicarbonate ion, HCO31-, from the baking soda. The sodium cation and the acetate anion are spectator ions that do not take part in the actual chemical change. |
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Please read entire procedure before you begin the experiment.
It is convenient to have a helper for this experiment; an extra pair of hands is very useful. This is particularly true when you need to steady the 2 liter bottle used to capture the CO2. Record each measurement on the Report Sheet as soon as you make the measurement. |
You will need to use the following.
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Get Ready
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Carry Out the Reaction
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Measure the Amount of CO2 Produced
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Calculate the mols of carbon dioxide
% yield = 100 x ( # moles carbon dioxide actual / # moles of carbon dioxide expected) alternately in terms of yield weights |
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your instructor. Paste the report in an email.
For people in Canvas you will submit an equiz inside Canvas for your report.
Chemical Reactions Report Sheet
Data
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Water used to fill plastic bottle: |
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1) |
ml |
ml |
ml |
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2) |
ml |
ml |
ml |
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3) |
ml |
ml |
ml |
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4) |
ml |
ml |
ml |
Total volume of plastic bottle |
ml |
ml |
ml |
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Volume of water left in bottle after CO2 was collected |
ml |
ml |
ml |
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Mass of baking soda used |
g |
g |
g |
Calculations
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Moles of baking soda, NaHCO3 used |
moles |
moles |
moles |
Moles of CO2 that can be made from this many moles of NaHCO3 (theoretical yield of CO2) ** Show how |
moles |
moles |
moles |
Volume of CO2 trapped in bottle |
ml |
ml |
ml |
Volume of CO2 trapped in bottle |
L |
L |
L |
Moles of CO2 trapped in bottle (actual yield of CO2) |
moles |
moles |
moles |
% yield of CO2 |
% |
% |
% |
**Calculation set-up for finding calculated or theoretical yield of CO2 for Trial 1.
Percent yield average
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Trial 1 |
Trial 2 |
Trial 3 |
Average Percent Yield |
%
yield of CO2 |
% |
% |
% |
% |