determine the molar volume of carbon dioxide gas and the amount of sodium carbonate in a sample.

Reading assignment: Julia Burdge, Chemistry 3rd edition, Chapter 10.
Goals
To determine the molar volume of carbon dioxide gas and the amount of sodium carbonate in a sample.
Equipment and Materials
Analytical balance, 50-mL graduated cylinder, gas generator and gas collection tray, carbonate source,
3.0 M hydrochloric acid, Alka-Seltzer tablet.
Discussion
Carbonates react with acids to produce carbon dioxide gas. An example is the reaction between sodium
carbonate and hydrochloric acid:
Na2CO3 (s) + 2 HCl (aq)  2 NaCl (aq) + H2O (l) + CO2 (g)
The molar volume (VM) of carbon dioxide can be found from by measuring the volume of the gas and the number
of moles of the gas:
2
2
CO
M
CO
V
V =
n
Equation 1
In this experiment we will not be measuring the volume at standard temperature and pressure (STP). But we can
calculate the volume at STP by taking into account a correction for temperature and pressure:
exp
exp
exp
273K P
V(STP)=V
T 760mmHg
          
Equation 2
Where the “exp” subscripts refer to the experimental temperature and pressure acquired in the laboratory.
Procedure
SAFETY PRECAUTIONS
Safety glasses are required for this experiment. Hydrochloric acid is a strong acid and can damage clothing or skin.
Students work in pairs on this experiment.
Sample Preparation

1. Prepare your sample of sodium carbonate by weighing out between 0.17 g and 0.18 g. Record the mass of your
   sample to 0.1 mg.
2. Carefully transfer your carbonate sample to a 75-mm test tube.
3. Pour 10 mL of 3.0 M HCl solution into a 200-mm test tube using a 10-mL transfer pipet.
4. Carefully slide the 75-mm test tube into the 200-mm test tube. Be sure not to allow any acid solution to enter
   the smaller test tube.
5. Place the two test tubes with the sample into a 100-mL beaker and weight the apparatus to the nearest 0.1 mg.