Carbon Dioxide - How to Prepare Carbon Dioxide Gas

Gas Preparation Instructions

This is the space-filling molecular structure for carbon dioxide.
This is the space-filling molecular structure for carbon dioxide. INDIGO MOLECULAR IMAGES LTD / Getty Images

These are instructions for preparing carbon dioxide gas (CO2) from calcium carbonate and hydrochloric acid.

Carbon Dioxide Reactants

Only two materials are needed to make carbon dioxide:

  • calcium carbonate (marble chips)
  • 5 M hydrochloric acid

Carbon Dioxide Gas Preparation

  1. Add 5 M hydrochloric acid to 5 - 10 g marble chips. Carbon dioxide gas is released by the chemical reaction.
  2. Collect the carbon dioxide from the upward displacement of air in a hood. Carbon dioxide is about 60% more dense than air, so it will fill the reaction container.

    Chemical Reaction

    2HCl + CaCO3 → CO2 + CaCl2 + H2O