Account for the following.
(i) CO is used in the extraction of metals.
(ii) CO is poisonous.
(iii) ${{CO}_{2}}$ is used in referigeration.
(i) CO being a good reducing agent, reduces several metal oxides (except alkali and alkaline earth metal oxides) into crude metal. That’s why it is used in the extraction of metals.
(ii) CO forms carboxy-haemoglobin complex with haemoglobin (the red pigment which carries oxygen) of blood which is about 300 times more stable than oxygen-haemoglobin complex and thus, it stops the supply of oxygen and hence, leads to death of the person.
(iii) Solid ${{CO}_{2}}$, produce cooling and sublimes directly into vapour state. That’s why it is used for refrigeration.