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Ch.18 - Chemistry of the Environment
Brown - Chemistry: The Central Science 14th Edition
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232당신이 사용하는 게 아니라요?교과서 변경
모든 교과서Brown 14th EditionCh.18 - Chemistry of the Environment문제 59
18장, 문제 59

In the following three instances, which choice is greener in each situation? Explain (a) Benzene as a solvent or water as a solvent (b) The reaction temperature is 500 K or 1000 K (c) Sodium chloride as a by-product or chloroform (CHCl3) as a by-product.

검증된 단계별 안내
1
Step 1: Consider the environmental impact of using benzene versus water as a solvent. Benzene is a volatile organic compound (VOC) and is toxic, posing health risks and environmental hazards. Water, on the other hand, is non-toxic and environmentally benign, making it a greener choice.
Step 2: Evaluate the energy consumption and environmental impact of reaction temperatures. A reaction at 1000 K requires more energy input than at 500 K, leading to higher energy consumption and potentially greater carbon emissions. Therefore, a lower temperature (500 K) is generally greener.
Step 3: Compare the environmental and health impacts of sodium chloride and chloroform as by-products. Sodium chloride (table salt) is non-toxic and widely used, whereas chloroform is a hazardous chemical with potential health risks and environmental concerns. Sodium chloride is the greener by-product.
Step 4: Summarize the greener choices: (a) Water as a solvent is greener than benzene. (b) A reaction temperature of 500 K is greener than 1000 K. (c) Sodium chloride as a by-product is greener than chloroform.
Step 5: Reflect on the importance of considering toxicity, energy consumption, and environmental impact when determining the greener choice in chemical processes.

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Solvent Properties

The choice of solvent significantly impacts the environmental footprint of a chemical process. Water is often considered a greener solvent due to its non-toxic nature, abundance, and ability to dissolve a wide range of substances. In contrast, benzene is a volatile organic compound that poses health risks and environmental hazards, making water the preferable choice in terms of sustainability.
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가이드 코스
02:49
Colligative Properties

Reaction Temperature and Energy Efficiency

The temperature at which a reaction occurs affects both the energy consumption and the rate of the reaction. Higher temperatures, such as 1000 K, typically require more energy input, which can lead to increased greenhouse gas emissions if fossil fuels are used. Conversely, lower temperatures, like 500 K, are generally more energy-efficient and environmentally friendly, making them a greener option.
추천 영상:
가이드 코스
03:48
Temperature vs Heat

By-products and Environmental Impact

The nature of by-products generated in a chemical reaction can greatly influence its overall environmental impact. Sodium chloride is a common, relatively benign by-product that can be easily managed and disposed of. In contrast, chloroform (CHCl3) is a hazardous substance with potential health risks and environmental concerns, making sodium chloride the greener choice in this context.
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가이드 코스
01:30
Production of Hydrogen Example
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In the following three instances, which choice is greener in a chemical process? Explain. (a) A reaction that can be run at 350 K for 12 h without a catalyst or one that can be run at 300 K for 1 h with a reusable catalyst.

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