Oxides of Carbon: CO₂, CO, and Carbonates

Introduction to Oxides of Carbon

Carbon forms two main oxides: carbon dioxide (CO₂) and carbon monoxide (CO). These oxides have different properties and uses, which are important in various chemical processes and applications.

Carbon Dioxide (CO₂)

• Properties:
  • Colorless and odorless gas.
  • Denser than air.
  • Slightly soluble in water, forming carbonic acid (H₂CO₃).
  • Non-flammable and does not support combustion.
• Uses:
  • Used in fire extinguishers due to its non-flammable nature.
  • Essential for photosynthesis in plants.
  • Used in carbonated drinks to provide fizz.
  • Employed in refrigeration and cooling systems.

Carbon Monoxide (CO)

• Properties:
  • Colorless, odorless, and tasteless gas.
  • Highly toxic and can be lethal when inhaled.
  • Slightly less dense than air.
  • Burns with a blue flame, producing carbon dioxide.
• Uses:
  • Used as a reducing agent in metallurgy.
  • Involved in the production of certain chemicals like methanol.
  • Used in gas mixtures for industrial purposes.

Carbonates

Carbonates are salts of carbonic acid containing the carbonate ion, CO₃²⁻. They are commonly found in minerals and are used in various industries.

• Examples:
  • Calcium carbonate (CaCO₃) - found in limestone and marble.
  • Sodium carbonate (Na₂CO₃) - used in glass making and as a water softener.

Testing for Carbon Dioxide

To test for carbon dioxide, bubble the gas through limewater (a solution of calcium hydroxide). If carbon dioxide is present, the limewater turns milky due to the formation of calcium carbonate.