Green chemistry principles Knowledge-Based Download PDF

Questions

1. 1.

   Which of the following synthetic strategies directly aligns with the green chemistry principle of reducing derivatives?

   • A) Running chemical reactions under extreme pressures to shorten reaction completion times.
   • B) Substituting bio-based catalytic pathways with stoichiometric mineral reagents.
   • C) Eliminating temporary protection and deprotection steps during a multi-step organic synthesis.
   • D) Installing post-reaction scrubbing units to treat toxic emissions after product isolation.
2. 2.

   Which of the following statements best reflects the green chemistry principle concerning safer solvents and auxiliaries?

   • A) Solvents should be selected primarily for high volatility so they can readily evaporate into the atmosphere after a reaction.
   • B) Hazardous auxiliaries are encouraged if they accelerate reaction rates, provided that downstream waste scrubbing systems are installed.
   • C) Auxiliary substances must always be added in stoichiometric excess to ensure complete dissolution and maximum equilibrium conversion.
   • D) Auxiliary substances should be eliminated wherever possible, and innocuous, environmentally benign alternatives should be selected when their use is unavoidable.
3. 3.

   Which statement best explains why catalytic reagents are preferred over stoichiometric reagents according to the principles of green chemistry?

   • A) Catalysts shift chemical equilibrium toward products to increase the theoretical yield of a reaction.
   • B) Catalysts operate in small amounts and are regenerated, significantly reducing chemical consumption and byproduct waste.
   • C) Catalysts completely eliminate the activation energy barrier required for chemical bond transformations.
   • D) Catalysts react irreversibly with toxic auxiliaries to neutralize hazardous impurities in the reaction mixture.
4. 4.

   Which of the following industrial practices best exemplifies the green chemistry principle of design for degradation?

   • A) Replacing volatile organic solvents with non-flammable ionic liquids during extraction
   • B) Employing reusable transition-metal catalysts to minimize stoichiometric reagent consumption
   • C) Manufacturing polylactic acid packaging materials that break down into benign substances in compost
   • D) Operating chemical synthesis reactors at ambient temperature and pressure to conserve energy
5. 5.

   Which statement correctly describes the green chemistry principle of atom economy?

   • A) It prioritizes neutralizing and treating hazardous chemical waste after a synthesis rather than preventing byproduct formation.
   • B) It evaluates reaction efficiency by determining the proportion of reactant atoms incorporated into the desired final product.
   • C) It measures the total mass of auxiliary solvents and separation agents recycled during product purification.
   • D) It focuses solely on maximizing the percent yield of a reaction regardless of the stoichiometric mass of generated byproducts.