Green Chemistry Unit 3 Quiz

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Questions and Answers

What is a primary goal for designing chemical reactions in terms of energy requirements?

Minimize energy consumption (correct)

Increase the reaction time

Maximize the number of reaction steps

Utilize high pressure conditions

Which of the following methods can supply energy to a reaction more efficiently than conventional methods?

Thermal energy

Pressure cooking

Utrasonic energy (correct)

Ambient temperature reactions

How does microwave heating differ from conventional heating in terms of heat transfer?

Microwave heating directly heats solvent molecules in the mixture. (correct)

Conventional heating directly heats the solvent molecules.

Microwave heating achieves heat loss through convection.

Microwave heating heats the vessel rather than the mixture.

What is a disadvantage of conventional heating compared to microwave heating?

Slow heating rate Signup and view all the answers

Which statement best describes the relationship between catalyst use and energy efficiency?

Catalysts help minimize energy requirements and improve selectivity. Signup and view all the answers

What characteristic of microwave heating contributes to better energy efficiency?

Uniform heating Signup and view all the answers

Which design principle is associated with minimizing waste and maximizing efficiency in reactions?

High atom economy Signup and view all the answers

What is one major advantage of utilizing microwave reactions over conventional methods?

They can achieve yield in less time. Signup and view all the answers

Which type of reaction can be considered to have 100% atom economy?

Rearrangement reactions Signup and view all the answers

What is the main aim of designing safer chemicals?

To ensure chemicals are efficient while reducing toxicity Signup and view all the answers

Why is the use of phosgene gas in polymer synthesis problematic?

It is a toxic gas harmful to health and the environment Signup and view all the answers

How can hazardous substances in chemical reactions be minimized?

By redesigning the reaction to reduce steps and substitute toxic chemicals Signup and view all the answers

What characteristic is NOT desired in a safer chemical?

High levels of hazardous materials Signup and view all the answers

Which of the following statements is true regarding the synthesis of urethane?

It can be synthesized using CO2 as a non-toxic alternative Signup and view all the answers

The outcome of using thalidomide during pregnancy resulted in:

Birth defects in children born to mothers using the drug Signup and view all the answers

Which method does not enhance safety in chemical processes?

Increasing the number of steps in synthesis Signup and view all the answers

What is the purpose of using plant-based natural coagulants in water treatment?

They are biodegradable and environmentally friendly. Signup and view all the answers

What is the primary benefit of minimizing wastage in chemical synthesis?

It reduces the need for expensive storage. Signup and view all the answers

How is E-factor defined in the context of chemical synthesis?

It is the ratio of waste produced to the mass of the product. Signup and view all the answers

What does a higher E-factor value indicate?

More by-products are formed. Signup and view all the answers

Why is atom economy important in green chemistry?

It fully utilizes all chemicals in the reaction. Signup and view all the answers

Which step is NOT part of calculating atom economy?

Estimating the final selling price of the product. Signup and view all the answers

What does a 100% atom economy signify in a reaction?

All reactants are converted into products. Signup and view all the answers

What is the impact of discharging large by-products into the environment?

It may cause pollution and harm human health. Signup and view all the answers

What is a primary goal of green chemistry?

To reduce or eliminate hazardous substances Signup and view all the answers

Which of the following principles is emphasized in the framework of green chemistry?

Principle 1: Prevention of waste Signup and view all the answers

What environmentally harmful chemical was commonly used in dry cleaning before the adoption of green alternatives?

Perchloroethylene (PERC) Signup and view all the answers

Which biodegradable plastic is mentioned as a green alternative to petrochemical-based plastics?

Polylactic acid (PLA) Signup and view all the answers

What is a significant improvement in green chemistry related to the synthesis of ibuprofen?

Higher efficiency in the synthesis process Signup and view all the answers

What problem is addressed by using PYROCOOL FEF in firefighting?

Reduction of harmful environmental side effects of existing foams Signup and view all the answers

How do eco-friendly paints differ from traditional oil-based paints?

They are non-toxic and do not release harmful vapors Signup and view all the answers

What is a downside of using alum in water treatment, according to green chemistry principles?

It can increase toxins and is linked to health issues. Signup and view all the answers

What is one of the primary advantages of using ultrasound assisted reactions?

Reaction is smooth and rapid Signup and view all the answers

Which of the following is considered a renewable starting material?

Carbon dioxide from natural sources Signup and view all the answers

Which method is considered greener for producing adipic acid?

Converting glucose from corn starch Signup and view all the answers

What is a significant environmental benefit of photochemical reactions?

Photons do not leave residues Signup and view all the answers

What advantage does ultrasound assisted chemistry provide in terms of energy consumption?

Reduced energy consumption Signup and view all the answers

Which plastic made from renewable resources is noted for its recyclability?

Polylactic acid (PLA) Signup and view all the answers

What characteristic of renewable resources allows them to be advantageous in production?

They are generated quickly in real-time Signup and view all the answers

What potential drawback does the conventional method for producing adipic acid present?

Benzene is carcinogenic Signup and view all the answers

What is a potential benefit of real-time analysis in chemical processes?

It helps manage reactions and improve safety. Signup and view all the answers

Which insecticide is derived from the chrysanthemum flower?

Pyrethrum Signup and view all the answers

What incident prompted increased awareness regarding chemical safety in manufacturing units?

The Union Carbide gas leak in Bhopal. Signup and view all the answers

What is a consequence of improperly designed chemical synthesis?

Increased risk of hazardous substance release. Signup and view all the answers

Which chemical substance was involved in the Bhopal gas tragedy?

Methyl isocyanate Signup and view all the answers

How can real-time monitoring affect chemical reactions?

It can optimize conditions for better yield. Signup and view all the answers

What should be the priority when selecting substances for chemical processes?

Minimizing potential chemical accidents. Signup and view all the answers

What characterizes inherently safer chemistry principles?

Selection of safer substances to limit accident risks. Signup and view all the answers

Study Notes

UNIT 3: GREEN CHEMISTRY

Green chemistry is the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and applications of chemical products.
Green chemistry aims to minimize environmental pollution.
Green chemistry was developed by Paul Anastas and John Warner in 1998.
Green chemistry principles provide a framework for creating greener chemical products, processes, and products.

Introduction to Green Chemistry
Principles of Green Chemistry
Emphasis on principles 1, 2, 5, 6, and 9
Real-world cases: Surfactants for CO2
Real-world cases: Designing for environmentally safe marine antifoulants
Real-world cases: Biodegradable plastics
Biodiesel synthesis and use

CONTENT 1: INTRODUCTION TO GREEN CHEMISTRY

Green chemistry is the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and applications of chemical products.
Green chemistry is environmentally friendly synthesis.
Environmental pollution is minimized to ensure environmentally responsible chemical processes.
Developed in 1998 by Paul Anastas and John Warner.

IMPORTANCE OF GREEN CHEMISTRY IN DAILY LIFE

Green dry cleaning of clothes
- A green commercial approach uses CO2 along with surfactants.
- The previous solvent Perchloroethylene (PERC) is a groundwater contaminant and suspected carcinogen.
Biodegradable Plastics
- PLA (polylactic acid) can be a substitute for petrochemical plastics.
- Eco Flex is a biodegradable polyester film with high resistivity.

INTRODUCTION (CONTINUED)

Medicine: Green chemistry plays a crucial role in pharmaceuticals.
- It aims to develop medicines with high efficiency and reduced side effects. Efficient synthesis involving fewer steps, with high efficiency of the synthesis. Example: Ibuprofen can be synthesized through 3 steps instead of 6.
Greener way to putting out fires:
- Existing firefighting foams have detrimental environmental impacts. PYROCOOL FEF is designed as a greener fire-fighting foam.
Eco-friendly paints:
- Oil-based paints have volatile organic compounds (VOCs) and heavy metals such as As, Pb, and Cr. They negatively affect human organs. Nerolac is presented as an eco-friendly, non-toxic, paint.
Getting clear water from turbid water:
- Alum is used in water treatment for coagulation/ clarification. However, Alum increases toxins in treated water and can lead to Alzheimer's.
- Natural coagulants, such as Tamarind seed kernel powder, are a biodegradable and environmentally friendly alternative.

PRINCIPLE 1: PREVENTION OF WASTE

It's more advantageous to prevent waste than to treat it later.
Waste (by-products or unreacted starting material) discharged into the atmosphere, sea, or land causes environmental pollution, harms human health, and increases manufacturing costs.
Minimizing waste generation in chemical synthesis is crucial for the environment and human health.
E-factor (environmental factor): Measures the amount of waste created in a process. A higher E-factor indicates more waste. Ideally, the E-factor should be close to zero.

PRINCIPLE 2: ATOM ECONOMY

Atom economy quantifies the efficiency of the process by incorporating the starting materials and reagents into the final product. A higher atom economy implies a more efficient process, generating less waste.
Calculating Atom economy:
- Write a balanced chemical equation.
- Calculate the molecular weights of all reactants and desired product.
- Apply the formula.

PRINCIPLE 3: LESS HAZARDOUS CHEMICAL SYNTHESIS

Chemical reactions should avoid generating harmful products or by-products and optimize processes while minimizing toxic substances. (Using cleaner, or less toxic, materials is preferred).
Example: Replacing phosgene with CO2 in polyurethane synthesis.

PRINCIPLE 4: DESIGNING SAFER CHEMICALS

Chemical products should be designed to maintain their function while minimizing toxicity.
Safer chemicals cause minimal negative impact on human health and the environment.
Example: Replacing harmful solvents like thalidomide.

PRINCIPLE 5: SAFER SOLVENTS AND AUXILIARIES

Use of auxiliary substances (e.g., solvents) should be minimized or eliminated wherever practical.
The use of harmless or non-toxic solvents is preferred.
Typical problems with solvents: Expense, Depletion of Fossil Fuels, Toxicity, Flammability, Carcinogenic potential, and Ozone Depletion.
The preferred solvents are readily available, cheap, easily separable, reusable, non-toxic, inert and do not pollute the environment or cause health hazards.

PRINCIPLE 6: DESIGN FOR ENERGY EFFICIENCY

Minimize energy consumption and use environmentally friendly energy sources (e.g., photochemical, microwave, ultrasound).
Conduct chemical reactions at ambient temperature and pressure.
Use catalysts to lower energy requirements.
Fewer steps mean less energy is required for the reaction, which also lowers waste.

PRINCIPLE 7: USE OF RENEWABLE FEEDSTOCKS

Prefer raw materials from renewable sources over non-renewable ones, minimizing environmental impact.
Use bio-based starting materials (e.g., Corn starch).
Example: Utilizing renewable feedstocks like corn starch as a source of adipic acid for making a biodegradable plastic.

PRINCIPLE 8: REDUCE DERIVATIVES

Minimize the use of blocking groups, protection/deprotection, or temporary modification of chemical processes, as these steps consume reagents and generate waste.
Protective groups are used to protect specific functional groups during a reaction sequence but need to be subsequently removed which requires more steps in the process, more reagents and more waste..

PRINCIPLE 9: CATALYSIS

Catalytic reagents are superior to stoichiometric ones.
Catalysts increase reaction rates and yield.
Catalysts create more selectivity, and reduce the amount of waste products.
Stoichiometric syntheses can be slow, and generate significant waste..

PRINCIPLE 10: DESIGN FOR DEGRADATION

Chemical products should break down quickly and efficiently after they've completed their function.
The degradation products must be environmentally harmless.
Chemical products should be synthesized with environmentally benign degradation products.
Example: Insecticides, Organophosphates, carbamates, and organochlorides.

PRINCIPLE 11: REAL-TIME ANALYSIS FOR POLLUTION PREVENTION

Real-time analysis helps monitor processes and prevent the formation of hazardous substances during chemical reactions.
In-process, real-time analysis can prevent accidents and stop reactions.
Real-time analysis techniques can be used to manage processes and improve efficiency.

PRINCIPLE 12: INHERENTLY SAFER CHEMISTRY FOR ACCIDENT PREVENTION

Design chemical processes to minimize the potential for accidents (e.g., releases, explosions, fires).
Prioritize using safer substances and minimizing dangerous process conditions.
Minimize the potential for dangerous releases, explosions, or fires. Example: Bhopal gas tragedy, Flixborough accident.

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Description

This quiz focuses on the principles of Green Chemistry, highlighting key concepts introduced by Paul Anastas and John Warner. Participants will explore the significance of reducing hazardous substances and the real-world applications of these principles, such as biodegradable plastics and biodiesel synthesis.