Major Classes of Contaminants and EPA Pollutant Classification Quiz

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Which property of a substance determines the amount of enthalpy/heat energy needed to vaporize a quantity of liquid at a constant temperature?

Vapor Pressure

Heat of Vaporization (correct)

Volatility

Vapor Density

What equation is used to relate concentration in liquid and vapor phases when discussing the properties of pollutants?

Rutherford Equation

Newton's Equation

Einstein's Equation

Clausius-Clapeyron Equation (correct)

Which type of toxicants have a higher affinity for fat according to the text?

Inorganic Toxicants

Metallic Toxicants

Organic Toxicants (correct)

Biological Toxicants

How can the vapor density of a substance be approximated?

By comparing gas densities Signup and view all the answers

What does Henry's Law describe in terms of gas solubility?

Solubility of gases in different solvents Signup and view all the answers

Which of the following is NOT a major class of contaminants?

Radioactive isotopes Signup and view all the answers

According to the EPA classification, which of the following is NOT a category of pollutants?

Greenhouse gases Signup and view all the answers

Which of the following statements about refrigerants is TRUE?

Refrigerants were originally chlorine-based but are now replaced with hydrogen. Signup and view all the answers

What is the primary concern with chlorofluorocarbons (CFCs)?

They are highly persistent in the environment. Signup and view all the answers

Which of the following statements about the EPA's principles of green chemistry is TRUE?

It encourages the use of less toxic and biodegradable substances. Signup and view all the answers

What is the primary concern with hydrogen-based refrigerants?

They are highly combustible. Signup and view all the answers

What substances are identified as being toxic at the ppm level?

PCBs and dioxins Signup and view all the answers

What is the main source of dioxin contamination?

Stationary sources such as chemical processes involving chlorine Signup and view all the answers

In 1971, what category of PCB usage accounted for 90% of PCB usage in the US?

Controllable closed systems like capacitors and transformers Signup and view all the answers

Which of the following is NOT a physicochemical property of PCBs?

High electrical conductivity Signup and view all the answers

What is the most toxic form of dioxin mentioned in the text?

TCDD (2,3,7,8-tetrachlorodibenzo[1,4]dioxin) Signup and view all the answers

What makes certain PCB congeners more toxic than others?

Having chlorine substituents in the non-ortho positions Signup and view all the answers

What is the octanol-water partition ratio used to express?

The lipophilicity of a compound Signup and view all the answers

What does a positive value for log Kow indicate?

The compound is hydrophobic Signup and view all the answers

What is the Odor Index (OI) based on?

The vapor pressure of the pollutant Signup and view all the answers

What does the Langmuir Isotherm assume?

The adsorbed layer is one molecule thick Signup and view all the answers

What does the Freundlich Isotherm describe?

A heterogeneous adsorbent surface with lateral interactions Signup and view all the answers

What is the primary application of activated carbon?

Water and air purification Signup and view all the answers

What is the composition of silica gel?

Amorphous form of silicon dioxide Signup and view all the answers

What is the primary application of zeolites?

Catalysis in chemical processes Signup and view all the answers

Which of the following is an example of an organic pollutant?

All of the above Signup and view all the answers

What is the purpose of the BET Isotherm?

To determine the adsorbent surface porosity Signup and view all the answers

What is the relationship between pH and solubility of pollutants?

Decreasing pH increases the solubility of some pollutants. Signup and view all the answers

Which of the following statements about the equilibrium of $CO_2$ dissolution in water is correct?

$CO_2(g) \rightleftharpoons CO_2(aq) \rightleftharpoons H_2CO_3 \rightleftharpoons HCO_3^- \rightleftharpoons CO_3^{2-}$ Signup and view all the answers

Which statement best describes the relationship between $K_c$ (equilibrium constant) and strong vs. weak acids in dissolving salts of weak acids?

Weak acids generally produce smaller $K_c$ values compared to strong acids. Signup and view all the answers

Which of the following statements about physisorption and chemisorption is incorrect?

Chemisorption involves multi-layer adsorption on the surface. Signup and view all the answers

What is the primary purpose of the Winkler method?

To measure the dissolved oxygen content in water. Signup and view all the answers

Which of the following statements about Total Organic Carbon (TOC) analysis is correct?

TOC can be analyzed using photocatalytic oxidation or high temperature combustion. Signup and view all the answers

What is the primary interference in the Chemical Oxygen Demand (COD) test?

Chloride Signup and view all the answers

Which of the following statements about Biochemical Oxygen Demand (BOD) is correct?

BOD measures the amount of oxygen consumed by bacteria during aerobic decomposition of organic matter. Signup and view all the answers

Which of the following reactions is involved in the Winkler method for measuring dissolved oxygen?

All of the above reactions are involved in the Winkler method. Signup and view all the answers

What is the relationship between the equilibrium constants ($K_c$) for the dissolution of $CaCO_3$ in strong and weak acids?

$K_c$ for strong acid is greater than $K_c$ for weak acid. Signup and view all the answers