Can You Determine the Mole Ratio for a Chemical Reaction?


In this experiment, you will react baking soda (NaHCO3) with hydrochloric acid (HCl) and produce salt (NaCl), You will determine the moles of reactants used and product produced through careful measurement of masses and by dividing by the appropriate formula weights.



Sodium bicarbonate (NaHCO3)                                    18x150 mm or larger test tubes (3)

3 M hydrochloric acid                                                   Balance with 0.01-gram precision



Caution: Put on your goggles and apron now!

  1. Review with your instructor the proper methods of heating and boiling liquids in test tubes. Review the safe handling of acids.
  2. Label three 18x150 mm test tubes (#1, #2, #3).
  3. Measure and record in the data table the masses of each of the labeled tubes to the nearest hundredth of a gram.
  4. Add to each test tube just enough baking soda to fill the curved bottom to the test tube.
  5. Measure and record in the table the masses of each respective tube with baking soda.
  6. Determine the mass of baking soda in each test tube by recording the differences between the measurements in steps #5 and #3. If necessary, adjust the mass of baking soda so that it is greater than 0.25 grams, but not more than 0.50 grams.

Warning: hydrochloric acid is caustic and corrosive. Avoid contact and immediately rinse all spills with copious amounts of water.

  1. To test tube #1, add 3 M HCl one drop at a time, allowing the drop to run down the inside wall of the test tube. Listen and watch the reaction. Gently agitate the tube after each drop until the reaction stops. Continue to add drops until there is no evidence of any further reaction. Describe the test tube contents and save it for step #9.
  2. Repeat the procedures in step #7 with test tubes #2 and #3.
  3. Evaporate off the fluid in each test tube by gentle heating above the Bunsen burner flame, slowly circling in an out of the heat. There must be no eruption of fluid out of your test tube. Proceed until dry.

Caution: Make sure that the open end of the test tube is not pointed at anyone.

  1. Remove the test tube from the flame and test for water vapor by inverting a clean, dry test tube over the mouth of your test tube. If you see condensation, continue the drying procedure for an additional five minutes and test again. Save your test tube for step #12.
  2. Perform steps #9 and #10 for test tubes #2 and #3. The test tubes should be cool enough to handle and mass after 5 minutes. Describe the test tube contents.
  3. Measure and record the mass for each test tube.
  4. Clean up you lab area.


Data Table


Test tube #1

Test tube #2

Test tube #3

Mass of test tube and baking soda




Mass of empty test tube




Mass of baking soda




Mole of baking soda




Mass of test tube and Sodium chloride




Mass of empty test tube




Mass of sodium Chloride




Moles of sodium chloride




Experimental mole ratio of NaHCO3 to NaCl




Theoretical mole ratio of NaHCO3 to NaCl





Calculations (Help)








  1. Explain any errors in your experiment greater than 10% (Help)
  2. What do caustic and corrosive mean? (look it up in the dictionary)
  3. What was the gas produced in this experiment? What type of test could you do to identify this gas?(Help)
  4. Why must you never weigh hot objects on the balance? (We had this question before)
  5. Write the balanced equation for this reaction. (Help)
  6. If you have 20 grams of hydrochloric acid and 20 grams of sodium bicarbonate, do you have the same number of moles?(Help)