Answer: Design processes that reduce or eliminate hazardous substances.
- A Use only natural substances in manufacturing
- B Design processes that reduce or eliminate hazardous substances
- C Maximize reaction by-products for economic monitoring
- D Replace all existing chemicals with inorganic alternatives
Correct answer: B. Design processes that reduce or eliminate hazardous substances
Explanation: Green chemistry, as defined by Anastas and Warner (1998), focuses on designing chemical products and processes that minimise or eliminate hazardous substances. Its 12 principles include atom economy, waste prevention, safer solvents, catalysis, and use of renewable feedstocks.
Classical smog is a reducing mixture of SO₂ and fog, while photochemical smog is an oxidising mixture generated by UV-driven reactions of NOx and hydrocarbons.
Concept context
Understand how human activities alter the atmosphere, water, and soil. Covers air pollutants, smog types, ozone depletion, acid rain, greenhouse effect, water and soil pollution, and the principles of green chemistry.