How to Prepare Carbon Dioxide Gas

A physical representation of a molecular structure
This is the space-filling molecular structure for carbon dioxide.

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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)
  • 5M hydrochloric acid

Carbon Dioxide Gas Preparation

  1. Add 5M hydrochloric acid to 5g-10g 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% denser than air, so it will fill the reaction container.

Chemical Reaction

2HCl + CaCO3 → CO2 + CaCl2 + H2O