Textbook Question
The concentration of H2O in the stratosphere is about 5 ppm. It undergoes photodissociation according to: H2O(g) → H(g) + OH(g) (b) Using Table 8.3, calculate the wavelength required to cause this dissociation.
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Ch.18 - Chemistry of the Environment
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232
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Table of contents
- Ch.1 - Introduction: Matter, Energy, and Measurement140
- Ch.2 - Atoms, Molecules, and Ions192
- Ch.3 - Chemical Reactions and Reaction Stoichiometry172
- Ch.4 - Reactions in Aqueous Solution156
- Ch.5 - Thermochemistry151
- Ch.6 - Electronic Structure of Atoms137
- Ch.7 - Periodic Properties of the Elements127
- Ch.8 - Basic Concepts of Chemical Bonding143
- Ch.9 - Molecular Geometry and Bonding Theories167
- Ch.10 - Gases147
- Ch.11 - Liquids and Intermolecular Forces97
- Ch.12 - Solids and Modern Materials129
- Ch.13 - Properties of Solutions126
- Ch.14 - Chemical Kinetics175
- Ch.15 - Chemical Equilibrium107
- Ch.16 - Acid-Base Equilibria127
- Ch.17 - Additional Aspects of Aqueous Equilibria133
- Ch.18 - Chemistry of the Environment88
- Ch.19 - Chemical Thermodynamics140
- Ch.20 - Electrochemistry137
- Ch.21 - Nuclear Chemistry99
- Ch.22 - Chemistry of the Nonmetals66
- Ch.23 - Transition Metals and Coordination Chemistry69
- Ch.24 - The Chemistry of Life: Organic and Biological Chemistry11
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232Not the one you use?Change textbook
Chapter 18, Problem 80
The water supply for a midwestern city contains the following impurities: coarse sand, finely divided particulates, nitrate ions, trihalomethanes, dissolved phosphorus in the form of phosphates, potentially harmful bacterial strains, dissolved organic substances. Which of the following processes or agents, if any, is effective in removing each of these impurities: coarse sand filtration, activated carbon filtration, aeration, ozonization, precipitation with aluminum hydroxide?
Verified step by step guidance1
Identify the type of impurity and match it with the appropriate removal process.
Coarse sand can be removed by coarse sand filtration, which physically separates larger particles from water.
Finely divided particulates can be removed by precipitation with aluminum hydroxide, which helps in coagulating and settling these particles.
Nitrate ions are typically not removed by the processes listed, but biological denitrification or ion exchange methods are effective.
Trihalomethanes can be removed by activated carbon filtration, which adsorbs organic compounds and chlorine by-products.
Dissolved phosphorus in the form of phosphates can be removed by precipitation with aluminum hydroxide, forming insoluble aluminum phosphate.
Potentially harmful bacterial strains can be effectively removed by ozonization, which disinfects water by oxidizing and destroying bacteria.
Dissolved organic substances can be removed by activated carbon filtration, which adsorbs organic molecules from the water.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Filtration
Filtration is a physical separation process that removes solid particles from liquids or gases by passing the mixture through a filter medium. Coarse sand filtration is effective for removing larger particles, such as sand and debris, while activated carbon filtration targets smaller organic compounds and impurities, including trihalomethanes and dissolved organic substances.
Chemical Precipitation
Chemical precipitation involves adding a chemical agent to a solution to form solid particles that can be removed from the liquid. In this context, aluminum hydroxide can precipitate dissolved phosphates, effectively reducing phosphorus levels in water, which is crucial for preventing eutrophication in aquatic systems.
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Ozonization and Aeration
Ozonization is a water treatment process that uses ozone gas to oxidize organic and inorganic contaminants, including bacteria and trihalomethanes, making them easier to remove. Aeration, on the other hand, introduces air into water, promoting the removal of volatile compounds and enhancing the oxidation of dissolved substances, which can help in reducing harmful bacterial strains.
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Related Practice
Textbook Question
In 1986 an electrical power plant in Taylorsville, Georgia, burned 8,376,726 tons of coal, a national record at that time. (b) If 55% of the SO2 could be removed by reaction with powdered CaO to form CaSO3, how many tons of CaSO3 would be produced?
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Textbook Question
The concentration of H2O in the stratosphere is about 5 ppm. It undergoes photodissociation according to: H2O(g) → H(g) + OH(g)
(c) The hydroxyl radical, OH, can react with ozone, giving the following reactions:
OH(g) + O3(g) → HO2(g) + O2(g)
HO2(g) + O(g) → OH(g) + O2(g)
What overall reaction results from these two elementary reactions? What is the catalyst in the overall reaction? Explain.
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Textbook Question
In 1986 an electrical power plant in Taylorsville, Georgia, burned 8,376,726 tons of coal, a national record at that time. (a) Assuming that the coal was 83% carbon and 2.5% sulfur and that combustion was complete, calculate the number of tons of carbon dioxide and sulfur dioxide produced by the plant during the year.
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Textbook Question
The estimated average concentration of NO2 in air in the United States in 2006 was 0.016 ppm. (a) Calculate the partial pressure of the NO2 in a sample of this air when the atmospheric pressure is 755 torr (99.1 kPa).
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