Chemistry · Ch 15 — Environmental Chemistry
Green Chemistry in Day-to-day Life
Green Chemistry in Day-to-day Life
A few contributions of green chemistry to our day-to-day life:
(1) Dry cleaning of clothes. Solvents like tetrachloroethylene, used in dry cleaning of clothes, pollute ground water and are carcinogenic. In its place, liquefied CO₂ with a suitable detergent is used as an alternative solvent -- liquefied CO₂ is not harmful to ground water. Nowadays H₂O₂ is also used for bleaching clothes in laundry, giving better results and using less water.
(2) Bleaching of paper. The conventional method of bleaching paper was done with chlorine. Nowadays H₂O₂ can be used for bleaching paper, in the presence of a catalyst.
(3) Synthesis of chemicals. Acetaldehyde is now commercially prepared by one-step oxidation of ethene, in the presence of an ionic Pd(II)/Cu(II) catalyst, in aqueous medium, giving a 90% yield:
(ethylene to acetaldehyde) -- a single, high-yielding step in place of a longer, harsher synthesis.
(4) Fuel choice. Instead of petrol, methanol is used as a fuel in automobiles.
(5) Pesticide choice. Neem-based pesticides have been synthesised, which are much safer than chlorinated-hydrocarbon pesticides. …
Worked out. (1) Dry cleaning of clothes: solvents like tetrachloroethylene, used in dry cleaning, pollute ground water and are carcinogenic; liquefied CO₂ with a suitable detergent is used instead, and is not harmful to ground water. H₂O₂ is now also used for bleaching clothes in laundry, giving better results and using less water. (2) Bleaching of paper: conventionally done with chlorine; now H₂O₂ can be used to bleach paper in the presence of a catalyst. (3) Synthesis of chemicals: acetaldehyde is now commercially prepared by one-step oxidation of ethene using an ionic Pd(II)/Cu(II) catalyst in aqueous medium, giving 90% yield (, ethylene to acetaldehyde). (4) Methanol is used as a fuel in automobiles instead of petrol. (5) Neem-based pesticides have been synthesised, safer than chlorinated hydrocarbon pesticides. The textbook closes the unit n …