Prabin Kalikote

We all know, carbon dioxide gas is heavier than air which cause it to flow to the lower surface. Therefore, carbon dioxide gas is found in lower surface like deep wells, mines, caves, etc.

Carbon dioxide gas is collected in the gas jar by the downward of air because it is heavier than air which cause it to flow to the surface.

When carbon dioxide is passed in lime water for a long time, the milky color disappears slowly due to the formation of water soluble calcium bicarbonate [Ca(HCO₃)₂].
                                CaCO₃ + H₂O + CO₂ --------> Ca(HCO₃)₂

When we pass CO₂ in lime water, it becomes milky white due to the formation of insoluble calcium carbonate (CaCO₃).

For commercial purpose, carbon dioxide gas is manufactured by heating calcium carbonate. During this process, calcium oxide i.e. lime or quick lime is also produced.
                            CaCO₃ -------------> CaO + CO₂

Any 3 chemical properties of carbon dioxide gas are:
        - CO₂ reacts with water and gives carbonic acid.
                    CO₂ + H₂O ----------> H₂CO₃
        - Green plants concert solar energy into chemical energy by photosynthesis. In this process CO₂ and water react to give starch and oxygen.
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Any 4 physical properties of CO₂ gas are:
        - It is colorless, odorless and tasteless gas.
        - It is heavier than air.
        - It is acidic in nature.
        - It is neither combustible nor a supporter of combustion.
        - It is soluble in wader and produce carbonic acid when dissolved in water.