i. Industrial chemistry is very important in the field of:
Answer: d) All of them
Explanation: Industrial chemistry is essential for producing a wide range of materials including medicines (pharmaceuticals), cement (construction), and glass (manufacturing), among many others.
ii. Halite (rock salt) in Pakistan is obtained from:
Answer: a) Lithosphere
Explanation: Halite (rock salt) is a mineral obtained from the lithosphere (Earth's crust). In Pakistan, major deposits are found in
the Salt Range (e.g., Khewra Salt Mine).
iii. The methods and applications to avoid accidents in chemical industry is termed as:
Answer: c) Chemical safety
Explanation: Chemical safety encompasses the methods, practices, and applications designed to prevent accidents, injuries, and exposure to hazardous chemicals in industrial settings.
iv. Butadiene is included in the class:
Answer: a) Olefins
Explanation: Butadiene (C₄H₆) is a diolefin (contains two double bonds) and is classified as an olefin (alkene). It is a key monomer in the production of synthetic rubber.
v. Polyvinyl chloride (PVC) is a polymer:
Answer: a) Addition
Explanation: PVC is produced by the addition polymerization of vinyl chloride monomer (CH₂=CHCl). No small molecule is eliminated during the process.
vi. Nylon 6,6 preparation needs:
Answer: d) Both a and b
Explanation: Nylon 6,6 is a polyamide synthesized by the condensation polymerization of adipic acid (a dicarboxylic acid) and hexamethylenediamine (a diamine).
vii. The percentage of gypsum in cement is:
Answer: a) 2-3%
Explanation: Gypsum (calcium sulfate dihydrate) is added to cement clinker in small amounts (about 2-3%) to regulate the
setting time of the cement.
viii. Vinegar is made by:
Answer: c) Fermentation
Explanation: Vinegar is produced by the fermentation of ethanol by acetic acid bacteria (Acetobacter). The ethanol is oxidized to acetic acid, giving vinegar its sour taste.
i. What are the petrochemicals? Explain their classes.
Answer: Petrochemicals are chemical products derived from petroleum (crude oil) and natural gas. They are the building blocks for thousands of industrial and consumer products. Their main classes include:
Olefins: Alkenes such as ethylene, propylene, and butadiene. They are highly reactive and used to make polymers (polyethylene, polypropylene), alcohols, and synthetic rubber. Aromatics: Compounds containing benzene rings, such as benzene, toluene, and xylenes. They are used to make plastics (polystyrene, PET), synthetic fibers (nylon), and detergents. Synthesis Gas (Syngas): A mixture of carbon monoxide and hydrogen, produced from natural gas or coal. It is used to make methanol and ammonia.
Others: Includes acetylene, naphthalene, and various other intermediates.
ii. What useful products are obtained from ethylene?
Answer: Ethylene (C₂H₄) is a key petrochemical and the most produced organic compound in the world. Useful products obtained from ethylene include:
Polyethylene: A major plastic used in packaging, bottles, and pipes. Ethylene Oxide: Used to make ethylene glycol (antifreeze, polyester) and surfactants. Ethylene Dichloride: Used to make vinyl chloride (PVC). Ethylbenzene: Used to make styrene (polystyrene plastics). Ethanol: Used as a solvent and fuel additive. Acetaldehyde: Used to make acetic acid and other chemicals.
iii. Enlist useful products obtained from benzene and it's derivatives.
Answer: Benzene and its derivatives are versatile petrochemicals used to produce:
Styrene: Used to make polystyrene (plastics, foam). Cumene: Used to make phenol (resins, adhesives) and acetone. Cyclohexane: Used to make nylon (polyamide fibers). Nitrobenzene: Used to make aniline (dyes, drugs). Alkylbenzenes: Used to make detergents. Phenol: Used to make resins, plastics, and pharmaceuticals. Benzene Hexachloride (BHC): Used as an insecticide. Maleic Anhydride: Used to make polymers and resins.
iv. How does chemical industry get raw materials for production of useful stuff?
Answer: The chemical industry obtains raw materials from several sources:
Petroleum and Natural Gas: The primary source of petrochemicals (ethylene, propylene, benzene, etc.). Minerals: Rock salt (halite), limestone, sulfur, phosphate rock, and bauxite are mined for various chemical processes. Air: Nitrogen and oxygen are separated from air by fractional distillation. Water: Used as a solvent, coolant, and reactant. Biomass: Plants and agricultural waste are sources of cellulose, starch, and oils. Metals: Iron ore, copper ore, and others are used to produce metals and metal compounds.
v. Explain the addition polymerization with an example.
Answer: Addition polymerization is a type of polymerization where unsaturated monomers (containing carbon-carbon double bonds) add to each other without the elimination of any small molecule. The polymer has the same empirical formula as the monomer.
Mechanism: It involves three steps: initiation (free radical or ionic), propagation, and termination. Example: Polymerization of ethylene (ethene) to form polyethylene.
Equation: n CH₂=CH₂ [source symbol unavailable] [-CH₂-CH₂-]ₙ Conditions: High pressure and temperature with a catalyst (e.g., Ziegler-Natta). Product: Polyethylene, a versatile plastic.
vi. Explain condensation polymerization with an example.
Answer: Condensation polymerization is a type of polymerization where monomers with at least two functional groups react to form a polymer, with the elimination of a small molecule (e.g., water, HCl, methanol).
Mechanism: It is a step-growth process where functional groups react with each other. Example: Formation of nylon 6,6 from adipic acid and hexamethylenediamine.
Equation: n H₂N-(CH₂)₆-NH₂ + n HOOC-(CH₂)₄-COOH [source symbol unavailable] [-NH-(CH₂)₆-NH-CO-(CH₂)₄-CO-]ₙ + 2n H₂O Product: Nylon 6,6 (a polyamide) and water.
vii. How is the Kevlar prepared? What are it's uses?
Answer: Kevlar is a strong, heat-resistant synthetic fiber (aromatic polyamide). It is prepared by the condensation polymerization of terephthaloyl chloride (benzene-1,4-dicarbonyl chloride) and para-phenylenediamine (benzene-1,4-diamine).
Equation: n H₂N-C₆H₄-NH₂ + n ClOC-C₆H₄-COCl [source symbol unavailable] [-NH-C₆H₄-NH-CO-C₆H₄-CO-]ₙ + 2n HCl Uses:
Bulletproof vests and body armor. Helmets and protective gear. Tires and brake pads. Ropes and cables. Aerospace composites. Sports equipment (e.g., tennis rackets, kayaks).
viii. Write the raw materials used in nail polish.
Answer: Nail polish is a complex mixture of several raw materials:
Film Formers: Nitrocellulose (cellulose nitrate) is the primary film former. Resins: Tosylamide/formaldehyde resin for adhesion and gloss. Plasticizers: Dibutyl phthalate (DBP) or camphor for flexibility. Solvents: Ethyl acetate, butyl acetate, and toluene to dissolve the ingredients. Pigments: Titanium dioxide, iron oxides, and organic pigments for color. Suspending Agents: Stearalkonium bentonite to keep pigments suspended. UV Stabilizers: To prevent color fading.
ix. Enlist of raw materials used for making lipstick.
Answer: Raw materials used for making lipstick include:
Waxes: Beeswax, carnauba wax, candelilla wax (for structure and shape). Oils: Castor oil, lanolin, jojoba oil (for emollience and texture). Fats: Cocoa butter, shea butter (for moisturizing). Pigments: Iron oxides, titanium dioxide, carmine, mica (for color). Preservatives: Parabens, tocopherol (vitamin E) to prevent spoilage. Fragrance: Essential oils or synthetic fragrances. Antioxidants: To prevent rancidity.
x. Write down the method for the preparation of lipstick.
Answer: The preparation of lipstick involves the following steps:
1. Mixing and Melting: The waxes, oils, and fats are melted together in a heated vessel.
2. Adding Pigments: The pigments are ground and added to the molten mixture.
3. Milling: The mixture is passed through a roller mill to ensure uniform dispersion of pigments.
4. Deaeration: The mixture is heated under vacuum to remove air bubbles.
5. Molding: The molten mixture is poured into molds and cooled.
6. Flame Treatment: The surface of the lipstick is briefly passed through a flame to give a glossy finish.
7. Packaging: The lipstick is placed in tubes and packaged.
(Note: No specific Concept Assessment Exercises were provided in the images for this unit. If they were provided, they would be added here.)
