Formaldehyde : A clear, colorless, aqueous solution of 40 percent formaldehyde is called formalin.
Formalin is used disinfectant, preservative for biological specimens, etc.
Formaldehyde is the first member of the aldehyde sequence. It is lie in green leaves of plants where its presence is supposed to be due to the reaction CO2 with water in presence of sunlight and chlorophyll.
