Exp. 19 Objectives

1
Exp. 19 Objectives

• To determine the percent calcium carbonate in a
  heterogeneous mixture.
• To determine the molar volume of carbon dioxide
  gas at 273 K and 760 torr.

2
Exp. 19 Introduction

• Calcium carbonate, commonly known as limestone,
  is probably the most prevalent simple inorganic
  compound found in the Earths crust.
• The reaction of HCl on calcium carbonate (CaCO3)
  produces CO2 gas
• CaCO3(s) 2HCl(aq) ? CaCl2 CO2 H2O

3
Exp. 19 - Introduction

• You will react an impure sample containing CaCO3
  with HCl. CO2 gas will evolve and displace water
  as shown in fig. 19.2.
• Using the volume of CO2, you will calculate the
  moles of CO2 generated and, using stoichiometric
  equation 19.1, calculate the moles and wt CaCO3
  in the sample.

4
Exp. 19 Procedural Notes

• Part A
• Set up the two apparati shown in figures 19.3 and
  19.4.
• Part B
• Generate CO2 gas by allowing HCl to come in
  contact with the sample.

5
Exp. 19 Procedural Notes

• Part C
• Determine the temperature of the water.
• Determine the pressure of the CO2 gas by
  adjusting the water level in the test tube to
  that of the water in the bath (fig. 19.7).
• Determine the CO2 gas volume by measuring the
  difference between how much water is left in the
  test tube and what the initial volume is.

6
Exp. 19 Procedural Notes

• Part D
• Measure the mass of the CO2-generating apparatus
  (fig. 19.3) and subtract from the initial weight,
  thus calculating the mass loss of the sample.

7
Exp. 19 Report Sheet

• Questions 1 and 5