CHEMISTRY
Target
After completing this experiment, you should be able to
verify experimentally the mass and mole relationships between reactants and
products in a chemical reaction.
Equipment
and Materials:
Balance Wire
gauze spatula
ring
stand eye
dropper iron
ring
graduated
cylinder burner
and tubing Crucible
with lid
Sodium
hydrogen carbonate 3 M
Hydrochloric acid
Safety
Wear your
goggles and apron at all times. Hydrochloric acid is caustic and corrosive.
Avoid contact with skin and breathing vapors. If any acid should spill on you,
immediately flush the are with water and
then notify your teacher. Keep long hair and loose clothing away from flame.
Procedure
1. Measure the mass of the crucible and lid. Record this
mass
2. Add 2 g of sodium hydrogen carbonate to the crucible.
Measure the mass of the crucible, lid and sodium hydrogen carbonate. Record
this mass
3. Carefully add the hydrochloric acid, with the dropper, to
the sodium hydrogen carbonate in the crucible until the bubbling stops.
4. Place the crucible in the wire gauze on the ring stand.
Place the lid on top of the crucible, but tipped slightly so that steam can
escape.
5. Gently heat the crucible with a small flame until only
a dry solid remains. Make sure no water droplets remain on the underside of the
lid.
6. Turn off the burner and allow the apparatus to cool for
at least 10 minutes. Determine the mass of the cooled assembly (crucible, lid
and solid).
8. Determine the mass of the product inside the crucible.
7. Rinse the residue down the drain. Clean your lab area.
Wash your hands.
Data and
observations: Make your own data table, and record observations in
your lab book.
Analysis
and Calculations.
1. Assuming the products are NaCl, CO2, and H2O, write a
balanced equation for this reaction.
2. What are the mole ratios of all products to all reactants
from this experiment?
3. Calculate the number of grams of NaCl (Theoretical
Yield) produced from 2.0 grams of NaHCO3
4. What the mass of
the product, NaCl, you determined from your experiment in step 8. (Experimental
Yeild)
8. Calculate the percent error in this experiment using this
formula
Reflection:
In this section you will summarize the
findings of the lab activity (should be closely tied to the purpose statement).
Try to relate the data to the theories behind the results. You must also
evaluate the information you gathered. What is the error (or errors) in your
data? Are there any anomalies (unexpected results) and if so why are they
there? Did you accidentally spill part of a reactant altering the volume
needed? Did you wait too long during part of the lab procedure? It is not wrong
to make mistakes during a lab procedure. However, it is wrong to falsify or
misrepresent results!