Topic 4 -Carbon dioxide and carbonates

CARBON DIOXIDE

• Uses:
  • fire extinguishers
  • fizzy drinks
  • baking
  • the manufacture of urea, an ingredient in many fertilisers and plastics
  • as a refrigerant. 

Carbon dioxide is prepared by the action of a dilute acid, such as hydrochloric acid, HCl, on marble chips. Marble chips are yet another form of calcium carbonate, CaCO3.

• Carbon dioxide is heavier than air, so it can be collected by ‘downward delivery’ shown in the diagram below. The vessel used to collect it is called a gas jar. Unfortunately, as it is an invisible gas, it is very difficult to tell when the jar is full. You can collect this gas over water, as it is only slightly soluble.

INDUSTRIAL PREPERATION OF CARBON DIOXIDE

Carbon dioxide is given off when calcium carbonate is heated very strongly. The solid remaining is quicklime, so carbon dioxide is obtained as a…