ACS CP ACS CP Environmental Chemistry & Sustainability 1 — Questions and Answers
Question 1: Which principle of green chemistry focuses on designing chemical syntheses to use and generate substances with little or no toxicity to human health and the environment?
- Atom economy
- Prevention
- Designing safer chemicals (Correct answer)
- Catalysis
Correct answer: Designing safer chemicals
Principle 4 of the 12 Principles of Green Chemistry focuses on designing safer chemicals that retain efficacy while minimizing toxicity.
Question 2: The Clean Air Act regulates which of the following as a National Ambient Air Quality Standard (NAAQS) criteria pollutant?
- Carbon dioxide
- Ozone (Correct answer)
- Hydrogen sulfide
- Radon
Correct answer: Ozone
Ground-level ozone is one of the six criteria pollutants regulated under NAAQS, along with particulate matter, CO, NO2, SO2, and lead.
Question 3: Biochemical oxygen demand (BOD) is used as a measure of:
- Dissolved oxygen saturation in clean water
- The amount of organic matter in a water sample (Correct answer)
- Nitrogen content in wastewater
- pH buffering capacity of a river
Correct answer: The amount of organic matter in a water sample
BOD measures the amount of dissolved oxygen consumed by biological organisms when decomposing organic matter in a water sample at a given temperature.
Question 4: Which heavy metal is commonly associated with methylation by anaerobic bacteria in sediments, leading to bioaccumulation in the food chain?
- Lead
- Cadmium
- Mercury (Correct answer)
- Chromium
Correct answer: Mercury
Mercury is methylated by sulfate-reducing bacteria in anaerobic sediments to form methylmercury, which bioaccumulates and biomagnifies in aquatic food chains.
Question 5: The Montreal Protocol primarily addresses the phase-out of substances that deplete:
- Tropospheric ozone
- Stratospheric ozone (Correct answer)
- Atmospheric methane
- Ground-level nitrogen oxides
Correct answer: Stratospheric ozone
The Montreal Protocol is an international treaty designed to phase out the production and use of ozone-depleting substances (ODS) that destroy stratospheric ozone.
Question 6: Atom economy, a key green chemistry metric, is calculated as:
- (Mass of desired product / Mass of all reagents) × 100%
- (Moles of product / Moles of limiting reagent) × 100%
- (Molecular weight of desired product / Sum of molecular weights of all reactants) × 100% (Correct answer)
- (Actual yield / Theoretical yield) × 100%
Correct answer: (Molecular weight of desired product / Sum of molecular weights of all reactants) × 100%
Atom economy = (MW of desired product / sum of MWs of all reactants) × 100%, measuring how many atoms in the reactants end up in the desired product.
ACS CP ACS CP Environmental Chemistry & Sustainability 1
Which principle of green chemistry focuses on designing chemical syntheses to use and generate substances with little or no toxicity to human health and the environment?