ACS CP ACS CP Environmental Chemistry & Sustainability 2 — Questions and Answers
Question 1: The EPA's Superfund program (CERCLA) is primarily used to:
- Regulate air emissions from chemical plants
- Clean up contaminated hazardous waste sites (Correct answer)
- Issue permits for new chemical facilities
- Monitor drinking water quality standards
Correct answer: Clean up contaminated hazardous waste sites
CERCLA (Comprehensive Environmental Response, Compensation, and Liability Act) established the Superfund program to clean up uncontrolled or abandoned hazardous waste sites.
Question 2: Which type of water treatment process uses microorganisms to break down organic contaminants?
- Coagulation/flocculation
- Reverse osmosis
- Activated sludge process (Correct answer)
- Ion exchange
Correct answer: Activated sludge process
The activated sludge process is a biological treatment method using aerobic microorganisms to decompose dissolved organic matter in wastewater.
Question 3: Which greenhouse gas has the highest global warming potential (GWP) over a 100-year time horizon among common industrial gases?
- Carbon dioxide (CO2)
- Methane (CH4)
- Nitrous oxide (N2O)
- Sulfur hexafluoride (SF6) (Correct answer)
Correct answer: Sulfur hexafluoride (SF6)
SF6 has a GWP of approximately 23,500 over 100 years, making it the most potent greenhouse gas regulated under the Kyoto Protocol.
Question 4: The principle of 'E-factor' in green chemistry measures:
- Energy efficiency of a reaction
- The ratio of waste generated to product formed (kg waste/kg product) (Correct answer)
- Environmental toxicity of reaction byproducts
- Electron transfer efficiency in electrochemical processes
Correct answer: The ratio of waste generated to product formed (kg waste/kg product)
The E-factor (environmental factor) is the ratio of kilograms of waste produced per kilogram of desired product, with lower values indicating greener processes.
Question 5: Volatile organic compounds (VOCs) are regulated as air pollutants primarily because they contribute to formation of:
- Acid rain
- Stratospheric ozone depletion
- Ground-level ozone and photochemical smog (Correct answer)
- Greenhouse gas accumulation
Correct answer: Ground-level ozone and photochemical smog
VOCs react with nitrogen oxides in the presence of sunlight to form ground-level ozone and photochemical smog, which are harmful air pollutants.
Question 6: Life cycle assessment (LCA) in green chemistry evaluates:
- The shelf life of chemical products under various storage conditions
- Environmental impacts of a product from raw material extraction to end-of-life disposal (Correct answer)
- The expected service life of laboratory instruments
- Regulatory compliance timelines for new chemical registrations
Correct answer: Environmental impacts of a product from raw material extraction to end-of-life disposal
LCA (cradle-to-grave analysis) assesses the environmental impacts of a product or process throughout its entire life cycle, from resource extraction to disposal.
ACS CP ACS CP Environmental Chemistry & Sustainability 2
The EPA's Superfund program (CERCLA) is primarily used to: