Aleksza
Honors Chemistry
2013-14
Can You Find the Mole Ratio? (INFORMAL LAB WRITE UP)
(Adapted from GPB Lab Episode 801)
Name:_______________________________MOD:_______Date of Exp:_______
Lab Partners:_______________________________________________________
Background:
In this experiment, baking soda (Sodium Bicarbonate) reacts with hydrochloric acid to
produce sodium chloride, carbon dioxide, and water. You will determine the moles of
reactant used and moles of product produced using both the lab data and stoichiometry
and compare the two.
Materials:
test tube, test tube holder, scoopula, 1M hydrochloric Acid, Sodium bicarbonate, pipette
or dropper bottle, Bunsen burner, burner tubing, matches, heat mitt, balance, weigh boats
Safety:
Goggles must be worn during this activity. Long hair and loose clothing must
be tied back. HCl will burn your skin. HOT GLASS LOOKS LIKE COLD
GLASS! Wash your hands after this activity.
Procedures
___1. Mass the empty test tube and write your results in the data table on Line 2.
___2. Add the baking soda to the test tube just to fill the bottom of the tube.
___3. Mass the test tube with the baking soda and write your results in the data table on
Line 1.
___4. Calculate the mass of the baking soda. Enter your results in the data table on Line
3.
___5.Add a drop of HCl to the test tube and slightly shake the test tube. Write your
observations on the space provided for observations.
___6.Continue to add drops of HCl and slightly shake until the reaction appears to be
stopped. BE PATIENT!
___7. Properly light the Bunsen burner.
___8. Heat the solution on the Bunsen burner until all the liquid is evaporated. It takes
a little while. (Wave solution over flame and point test tube away from people.)
___9. Place the test tube on a hot mitt to cool. TURN OFF the Bunsen burner.
___10. When the test tube is cool find the mass of the test tube plus the Sodium
Chloride. Enter your results in the data table on Line 4.
___11. Enter the original mass of the empty test tube on Line 5.
___12. Calculate the mass of the Sodium Chloride by subtracting the mass of the empty
test tube from the mass of the test tube plus the salt.
___13. Wash out the test tube, clean up your lab station and wash your hands.
Data Table:
Line 1
mass of test tube and baking soda
Line 2
mass of empty test tube
Line 3
MASS OF BAKING SODA
Line 4
mass of test tube and sodium chloride
Line 5
mass of empty test tube
Line 6
MASS OF SODIUM CHLORIDE
Reaction Observations:
Conclusion Questions:
1. Calculate the number of moles of baking soda (NaHCO3) used in the lab.
2. Calculate the number of moles of sodium chloride (NaCl) produced in the lab.
3. What is the experimental mole ratio of baking soda (NaHCO3) to sodium
chloride (NaCl)?
4. Write a balanced equation for the reaction that took place in the experiment.
5. According to the balanced equation, what is the theoretical mole ratio of
baking soda to sodium chloride? (Hint: look at the coefficients in #4)
6. Was the experimental mole ratio exactly the same as the theoretical mole
ratio? If not, give some possible SPECIFIC reasons.