Intro Lab: Name___________________________________________________________Period#______
NaHCO3(s) + HCl(aq)  NaCl(aq) + CO2(g) + H2O(l)
Be careful with the HCl…it can hurt you.
When we mix Sodium bicarbonate with hydrochloric acid it makes salt, water, and
carbon dioxide. The carbon dioxide being formed is the reason it fizzes. The carbon
dioxide leaves the reaction container and goes into the air in the room. If we heat up
the reaction container we can turn the water into water vapor which evaporates away.
This leaves behind just the sodium chloride in the container.
Visualize how big a molecule of NaHCO3 is compared to that of NaCl.
(It would probably be helpful to look at the periodic table and see their masses)
1. What is the mass of one molecule of NaHCO3?
2. What is the mass of one molecule of NaCl?
3. How many times larger (heavier) is sodium bicarbonate than sodium chloride?
4. If you had one pile with 100 sodium bicarbonate molecules and one pile with 100 sodium chloride molecules
which pile would be heavier?
5. How many times heavier would the larger pile be?
6. Draw a picture to represent the relative weights (we mean a circle 16 times bigger weighs 16 times as much)
of NaHCO3 and NaCl.
Notice in the example below how the oxygen in H2O is roughly 16 times larger than each hydrogen because an
oxygen atom is roughly 16 times heavier than a hydrogen atom.
Be sure to think about how big each of the circles should be in your drawings. We have drawn the H and O
sizes in the left box. This should give you a place to start when drawing NaHCO3.
H2O (example)
NaHCO3
NaCl
7. Think about the relative weight difference between NaHCO3 and NaCl. If I reacted 0.5 grams of NaHCO3
how many grams of NaCl should be produced?
You are now going to react hydrochloric acid with sodium bicarbonate to make sodium chloride.
NaHCO3(s) + HCl(aq)  NaCl(aq) + CO2(g) + H2O(l)
Be careful with the HCl…it can hurt you.
We will want to know the mass of two things in this experiment:
Sodium bicarbonate (at the start of the experiment)
Sodium chloride (at the end of the experiment)
YOU WILL NEED TO DETERMINE THE MASS OF SODIUM CHLORIDE FORMED WHEN THE
REACTION IS ALL DONE. THINK AHEAD OF TIME ABOUT HOW YOU WILL DO THIS.
Right now write down all of the things that you will have to know the mass of, when you will measure them, and
any calculations you might need to perform in order to get the masses.
Procedure:
Step 1. Make sure your evaporating dish is CLEAN and DRY! If it is not then you can wash it, heat it up, and then let
cool down.
Step 2. Put between 0.2g & 0.3 g of sodium bicarbonate into the evaporating dish. (Write the exact amount you are
using in Box #8)
Step 3. Slowly add HCl to the NaHCO3 (drop by drop) until all the bubbling (reacting) has stopped.
Step 4. Use the burner (on a low heat setting) to drive off all the liquid in the evaporating dish. Put a watch glass over
the evaporating dish so that you don’t loose any of the NaCl.
Step 5. Once the evaporating dish is cool enough to touch put it on the scale and weigh again.
8. What mass of NaHCO3 did you start with? (Be precise)
9. How much NaCl should you have ended up with?
(You need to calculate this)
10. How much did your sodium chloride actually weigh?
(Be precise.)
11. What is your percent error for this experiment?
(Got-shoulda)/shoulda
12. I would like to recover exactly 0.237 grams of sodium chloride. What mass of sodium
bicarbonate will you need to react to produce this amount?
13. Get that amount of NaHCO3 and react it. Use the same steps you used before to do the lab
over again. How much sodium chloride did you actually produce?
14. What was your percent error this time?