DO, BOD, Threshold Limit Value, COD:
- Dissolved Oxygen (DO) is the amount of oxygen that is dissolved in water.
- Biochemical
Oxygen Demand (BOD) is a measure of the amount of oxygen consumed by
microorganisms that decompose organic matter in water.
- Threshold Limit Value (TLV) is the maximum concentration of a pollutant that a person can be exposed to without suffering harm.
- Chemical
Oxygen Demand (COD) is a measure of the amount of oxygen needed to
oxidize all organic and inorganic substances in water.
Forest Resources and Its Uses:
- Forests provide a variety of resources, including timber, firewood, paper, and medicinal plants.
- Forests also play important roles in regulating the climate and water cycle.
- Sustainable forest management is important to ensure that forests can continue to provide resources for future generations.
Biotic Components:
- Biotic components refer to living organisms in an ecosystem.
- Producers are organisms that make their own food through photosynthesis.
- Consumers are organisms that eat other organisms.
- Decomposers break down dead organisms and recycle nutrients back into the ecosystem.
- Biotic components play crucial roles in maintaining the balance of an ecosystem.
Contaminant, Pollutant, Receptor, Sink, Particulate:
- A contaminant is any substance that is present in an environment where it does not belong.
- A pollutant is a contaminant that has harmful effects on the environment or living organisms.
- A receptor is an organism or part of the environment that can be affected by a pollutant.
- A sink is a part of the environment that can absorb or remove pollutants from the environment.
- Particulates are small solid particles or liquid droplets that are suspended in the air or water.
Layers of Atmosphere:
- The atmosphere is divided into five layers: troposphere, stratosphere, mesosphere, thermosphere, and exosphere.
- The troposphere is closest to the Earth's surface and contains 75% of the atmosphere's mass.
- The ozone layer is located in the stratosphere and helps protect the Earth from harmful UV radiation.
- The mesosphere is the coldest layer of the atmosphere and is where most meteoroids burn up.
- The thermosphere is the hottest layer of the atmosphere and contains the aurora borealis (northern lights).
- The exosphere is the outermost layer of the atmosphere and merges with space.
Methane and ethane are found in natural gas.
- Natural gas is taken from underground deposits and cleaned.
- The cleaned gas is moved through pipelines or compressed for storage.
- Methane and ethane can also be made by heating up oil or other substances, using a process called thermal or catalytic cracking.
- Anaerobic digestion can be used to make methane and ethane from organic matter by breaking it down without oxygen.
- Methane and ethane can also be made by heating coal in the presence of steam and air, which produces a gas that contains them and other gases.
Define gaseous fuel and its composition and uses:
- a. Water gas - a mixture of hydrogen and carbon monoxide produced by reacting steam with hot coal or coke. Used in industrial processes.
- b. Producer gas - a mixture of nitrogen, carbon dioxide, and hydrogen produced by partial combustion of solid fuels. Used in industrial heating.
- c. Natural gas - mainly composed of methane, with small amounts of ethane, propane, and butane. Used for heating, cooking, and electricity generation.
- d. Coal gas - a mixture of hydrogen, carbon monoxide, and methane produced by heating coal in the absence of air. Used for heating and lighting.
- e. Biogas - a mixture of methane and carbon dioxide produced by anaerobic digestion of organic waste. Used for heating and electricity generation.
- f. Acetylene - a gas composed of carbon and hydrogen, produced by reacting calcium carbide with water. Used for welding and metal cutting.
Formulas
- a. Water gas: CO + H2
- b. Producer gas: CO + H2 + N2
- c. Natural gas: mainly methane (CH4), but can also contain ethane (C2H6), propane (C3H8), and butane (C4H10), among others
- d. Coal gas: mainly carbon monoxide (CO), hydrogen (H2), and methane (CH4), but can also contain nitrogen (N2) and carbon dioxide (CO2), among others
- e. Biogas: mainly methane (CH4) and carbon dioxide (CO2), but can also contain small amounts of other gases, such as hydrogen sulfide (H2S)
- f. Acetylene: C2H2
- High energy content per unit of weight or volume.
- Low cost and availability.
- Stability in storage and transport.
- Easy to handle and use safely.
- Combustion efficiency, producing low levels of pollutants and ash.
- Non-toxic and non-corrosive.
- Renewable or sustainable.
- Easy to access and produce.
- Compatible with the technology and equipment used for its consumption.
- Low carbon footprint.
- Describe classification of fuel based on physical state and occurrence:
- Fuels can be classified based on their physical state as solids, liquids, or gases.
- Solid fuels include coal, wood, and biomass.
- Liquid fuels include petroleum, diesel, and ethanol.
- Gaseous fuels include natural gas, propane, and hydrogen.
- Fuels can also be classified based on their occurrence as renewable or non-renewable.
- Renewable fuels include biomass, biofuels, and wind and solar power.
- Non-renewable fuels include fossil fuels such as coal, oil, and natural gas.
Define fuel and characteristics of fuel:
- Fuel is a substance that releases energy when burned.
- It can be in the form of solids, liquids, or gases.
- The most common fuels are derived from fossil fuels, such as coal, oil, and natural gas.
Characteristics of a good fuel include high energy content, low cost, availability, ease of storage and transport, and safety in handling and use.
- Other important characteristics of fuel are its flash point, volatility, and combustion efficiency.
- Flash point is the temperature at which a fuel ignites.
- Volatility refers to a fuel's ability to vaporize and form flammable mixtures with air.
- Combustion efficiency is a measure of how effectively a fuel is burned to release energy.
Describe the process of vulcanization:
- Vulcanization is a chemical process that improves the strength and durability of rubber by cross-linking the polymer chains.
- Vulcanization was discovered by Charles Goodyear in the 19th century and revolutionized the rubber industry.
- Vulcanization
involves heating the rubber with sulfur or other cross-linking agents,
causing the polymer chains to bond together and form a network
structure.
- Vulcanization improves the elasticity, durability, and resistance to heat and chemicals of the rubber.
- Vulcanized rubber is used in tires, hoses, seals, and many other applications where strength and durability are required.
Describe the butyl Rubber, Buna-s, Neoprene rubber and its uses:
- Butyl rubber is a synthetic rubber made from isobutylene and small amounts of isoprene.
- Butyl rubber is highly impermeable to gases and liquids, making it useful in tire inner tubes, roofing membranes, and other applications where airtightness is important.
- Buna-s is a copolymer of styrene and butadiene, and is used in the production of tires, adhesives, and other applications where strength and flexibility are required.
- Neoprene rubber is a synthetic rubber made from chloroprene monomers.
- Neoprene rubber is highly resistant to heat, oil, and chemicals, making it useful in wetsuits, gaskets, and other applications where resistance to environmental factors is important.
Processing of rubber from latex:
- Natural rubber is obtained from the latex sap of rubber trees by tapping the trees and collecting the sap.
- The latex is treated with acid to coagulate the rubber particles and form a solid mass.
- The rubber mass is washed, dried, and pressed to remove excess water and impurities.
- The rubber is then rolled into sheets or formed into other shapes using heat and pressure.
- Synthetic rubber is produced by polymerizing monomers such as styrene, butadiene, or isoprene to form long chains of rubber-like molecules.
1.Polyethylene:
- Polyethylene is a thermoplastic polymer made from ethylene monomers.
- Polyethylene can be produced in high-density or low-density forms, depending on the reaction conditions.
- Polyethylene is used in packaging, construction, and consumer goods.
- Polyethylene can be extruded, molded, or blown into various shapes and sizes.
- Polyethylene can be recycled and reused in many applications.
2. PVC:
- PVC is a thermoplastic polymer made from vinyl chloride monomers.
- PVC is used in construction, packaging, and consumer goods.
- PVC can be rigid or flexible, depending on the amount of plasticizer added.
- PVC can be extruded, molded, or coated with other materials.
3.Teflon:
- Teflon is a brand name for a group of fluoropolymer resins made from tetrafluoroethylene monomers.
Teflon is known for its non-stick properties, making it useful in cooking and food processing.
Teflon is also used in industrial applications, such as coatings for pipes and wire.
Teflon has a high melting point and is resistant to chemicals and corrosion.
Teflon can be molded, extruded, or applied as a coating.
4. Polystyrene:
- Polystyrene is a thermoplastic polymer made from styrene monomers.
- Polystyrene can be produced in rigid or foam forms, depending on the reaction conditions.
- Polystyrene is used in packaging, insulation, and consumer goods.
- Polystyrene foam is also used in food service, such as cups and containers.
- Polystyrene can be extruded, molded, or foamed.
5. Urea-formaldehyde:
- Urea-formaldehyde is a thermosetting polymer made from urea and formaldehyde.
- Urea-formaldehyde is used in wood products, such as particleboard and plywood.
- Urea-formaldehyde is known for its strength, stability, and resistance to moisture.
- Urea-formaldehyde is cured using heat and pressure, making it rigid and stable.
- Urea-formaldehyde can be molded or applied as a coating.
6. Bakelite:
- Bakelite is a thermosetting polymer made from phenol and formaldehyde.
- Bakelite was the first synthetic plastic invented and was widely used in electrical and mechanical applications.
- Bakelite is highly heat-resistant and electrically insulating.
- Bakelite can be molded or cast into complex shapes and sizes.
- Bakelite has been largely replaced by newer materials but is still used in some niche applications.
7. Rubber:
- Rubber is a natural polymer made from the sap of rubber trees or synthetic polymers made from petrochemicals.
- Rubber is used in tires, hoses, gaskets, and many other applications.
- Rubber can be processed using different methods to achieve different properties, such as natural rubber, butyl rubber, or neoprene rubber.
- Rubber can be vulcanized to improve its strength and durability.
- Rubber is affected by temperature and can become brittle or soft depending on the conditions.
8. Natural rubber:
- Natural rubber is a polymer made from the sap of rubber trees, primarily grown in Southeast Asia.
- Natural rubber is highly elastic and can stretch up to six times its original length.
- Natural rubber is used in tires, footwear, and other applications where flexibility and strength are important.
- Natural rubber is vulnerable to degradation from heat, sunlight, and chemicals.
- Natural rubber can be vulcanized to improve its strength and durability.
Thermoplastics
- They are polymers that can be melted and reshaped multiple times without losing their properties.
- Thermoplastics have a linear or branched structure that allows them to move and flow when heated.
- Thermoplastics can be extruded, molded, or formed using heat and pressure.
- Examples of thermoplastics include polyethylene, polypropylene, and polystyrene.
Thermosetting
- They plastics are polymers that cannot be melted and reshaped once they have been cured.
- Thermosetting plastics have a cross-linked structure that prevents them from melting or flowing when heated.
- Thermosetting plastics require heat and pressure to cure and become rigid.
- Examples of thermosetting plastics include epoxy, phenolic, and melamine.
- Thermosetting plastics are more rigid and stable than thermoplastics, making them useful in applications where dimensional stability is important.
- Thermoplastics are more flexible and can be used in applications where impact resistance and flexibility are important.
Describe the disadvantages of plastics:
- Plastics can take hundreds of years to degrade in the environment, leading to pollution and harm to wildlife.
- Plastics can release harmful chemicals, such as bisphenol A (BPA) and phthalates, when they degrade or are heated.
- Plastics can be difficult to recycle and may require specialized equipment and facilities.
- Plastics can contribute to greenhouse gas emissions during production and incineration.
- Plastics can pose a risk to human health if ingested or inhaled, especially if they contain harmful chemicals.
- Plastics can be flammable and may release toxic fumes when burned.
- Plastics can be brittle and may crack or break over time, especially when exposed to sunlight.
- Plastics can be affected by temperature and may warp or deform when exposed to heat or cold.
- Plastics may not be biodegradable and can accumulate in landfills and oceans, creating environmental hazards.
- Plastics can be difficult to dispose of safely, leading to litter and waste.
Describe the advantages of plastics over traditional materials:
- Plastics are lightweight, making them easy to transport and handle.
- Plastics are durable and can resist wear, impact, and chemical damage.
- Plastics are flexible and can be molded into complex shapes, making them versatile and customizable.
- Plastics are inexpensive to produce and can be mass-produced, making them cost-effective for many applications.
- Plastics can be designed to have specific properties, such as resistance to UV radiation or fire.
- Plastics can be recycled and reused, reducing waste and environmental impact.
- Plastics can be made from renewable resources, such as plant-based polymers.
- Plastics can be sterilized, making them suitable for use in medical and food applications.
- Plastics can provide insulation and improve energy efficiency in buildings and vehicles.
- Plastics can be used to create new materials with unique properties and applications.
Describe the types of polymerization (addition and condensation):
Addition
- Addition polymerization involves the addition of monomers without the elimination of any small molecules.
- Addition polymerization can be initiated by heat, light, or chemical catalysts.
- Addition polymerization can produce polymers with high molecular weight and high purity.
- Examples of addition polymers include polyethylene, polypropylene, and polyvinyl chloride.
condensation
- Condensation polymerization involves the elimination of small molecules, such as water, during polymerization. Condensation
- polymerization can produce polymers with low molecular weight and high polydispersity.
- Examples of condensation polymers include nylon, polyester, and polyurethane.
- Condensation polymerization can be carried out using di- or polyfunctional monomers.
- Condensation polymerization can be carried out in solution or in the solid state.
- The properties of condensation polymers can be affected by the reaction conditions, such as temperature and pressure.
- The stereochemistry of the monomers can affect the properties of the resulting polymer.
- The structure of the monomers can affect the properties of the resulting polymer.
- The purity of the monomers can affect the properties of the resulting polymer.
- Polymerization can be a complex process that requires careful control of the reaction conditions.
- Polymerization can be used to create a wide range of materials with unique properties.
Define plastic and types of plastics:
- Plastic is a synthetic material made from polymers that can be molded into various shapes.
- Plastics have many applications, including in packaging, construction, and transportation.
- Plastics can be made from a variety of polymers, including polyethylene, polystyrene, and polyvinyl chloride.
- Plastics can be classified based on their properties, such as thermoplastics and thermosetting plastics.
- Thermoplastics can be melted and reshaped multiple times without losing their properties.
- Examples of thermoplastics include polyethylene, polypropylene, and polystyrene.
- Thermosetting plastics cannot be melted and reshaped once they have been cured.
- Examples of thermosetting plastics include epoxy, phenolic, and melamine.
- Plastics can also be classified based on their properties, such as amorphous and crystalline plastics.
- Amorphous plastics have a disordered molecular structure and are transparent and brittle.
- Examples of amorphous
Define polymer and polymerization:
Polymer:
- Polymers are large molecules made up of many smaller units called monomers that are joined together.
- Some common examples of polymers include plastics, rubber, and DNA.
- The properties of a polymer, such as its strength and flexibility, depend on the specific monomers used and how they are arranged.
- Polymers can be natural or synthetic, with some occurring in nature and others made in a laboratory or factory.
- Polymers have a wide range of uses, from packaging materials and medical devices to textiles and electronics.
Polymerization:
- Polymerization is a chemical reaction that joins together many small molecules, called monomers, to form a large molecule called a polymer.
- There are two main types of polymerization: addition and condensation.
- In addition polymerization, monomers are joined together without the loss of any byproducts, while in condensation polymerization, small molecules, such as water or alcohol, are formed as byproducts.
- Polymerization can be initiated by heat, light, or a catalyst, depending on the specific reaction.
- Polymerization is used to create a wide range of products, from plastics and adhesives to pharmaceuticals and paints.
