Materials Science and Industrial Chemistry

Nylon was the first completely synthetic fiber, invented by Wallace Carothers at DuPont in 1935. Rayon is semisynthetic (made from regenerated cellulose), while Polyester and Terycott came later. Nylon's discovery marked the beginning of the synthetic fiber industry.

Pyrex glass, also known as borosilicate glass, is highly heat-resistant due to its boron oxide content. This property makes it ideal for laboratory equipment and kitchenware. Other glass types like hard glass, flint glass, and bottle glass lack this specialized heat resistance.

Arsenic oxide is used as a refining agent in glass manufacture to remove air bubbles and improve clarity. It helps eliminate trapped gases during the melting process. Feldspar, potassium carbonate, and soda ash are raw materials, not refining agents.

Rayon is chemically composed of regenerated cellulose. It's produced from cellulose (usually from wood pulp) through a chemical process that creates a semisynthetic fiber. Glucose is a simple sugar, amylase is an enzyme, and peptin is also related to carbohydrates - none describe rayon's chemical nature.

Carbon black is extensively used as a reinforcing filler and filter in rubber tyres. It improves the strength, durability, and UV resistance of the rubber while also providing the characteristic black colour. The other options (graphite, coal, coke) are not typically used in tyre manufacturing.

Vulcanization is the chemical process where natural rubber is heated with sulphur to cross-link the polymer chains. This process significantly improves the rubber's properties including elasticity, strength, and temperature resistance. Charles Goodyear discovered this process in 1839.

Paraffin wax is a petroleum wax derived from petroleum crude oil. It consists of saturated hydrocarbons and is widely used in candles, cosmetics, and food packaging. Bees wax is natural (from bees), carnauba wax comes from palm leaves, and jojoba wax is extracted from jojoba seeds.

Rubber latex is coagulated using acetic acid to separate the solid rubber from the liquid serum. The acid neutralizes the negative charges on rubber particles, causing them to clump together. Strong acids like hydrochloric or sulphuric acid would degrade the rubber quality.

Rayon is known as artificial silk because it was developed as a cheaper alternative to natural silk. It has similar lustre, drape, and feel to silk but is produced from cellulose (wood pulp). Rayon is the first commercially successful semi-synthetic fibre.

Cobalt oxide (CoO or Co3O4) imparts a deep blue colour to glass when added in small amounts. This 'cobalt blue' glass has been used since ancient times. Iron oxide gives green/brown colours, cupric oxide produces blue-green, and nickel oxide can produce brown or violet colours depending on concentration.

Sodium hypochlorite (NaClO) is commonly used to bleach paper pulp, whitening it by oxidizing coloured impurities. Chlorine gas was historically used but sodium hypochlorite is safer and easier to handle. Caustic soda is used in pulping, not bleaching, and lime is used in recovery boilers.

Antimony sulphide (Sb2S3) is the combustible material at the tip of a safety match. When the match is struck against the striker surface (containing red phosphorus), friction generates heat that ignites the antimony sulphide, which then ignites the match stick. Sulphur is also present but antimony sulphide is the primary combustible.

Saccharine is synthesized from toluene (C7H8) through a series of chemical reactions including the oxidation of toluene derivatives. The sweetener was accidentally discovered in 1879. Benzene, phenol, and aniline are aromatic compounds but toluene is the specific starting material for commercial saccharine production.

The cement industry requires limestone (calcium carbonate) and clay (silica and alumina sources) as the two primary raw materials. These are heated in a kiln to form clinker, which is then ground with gypsum to produce cement. Individual materials alone (A or C) are insufficient, and gypsum (option B) is added later, not as a primary raw material.

Flint glass has a higher refractive index compared to crown glass, making it ideal for prisms and lenses where greater light bending is required. It contains lead oxide, which increases its refractive power and dispersion properties.

Powder type fire extinguishers (dry chemical extinguishers) are effective against petroleum fires because they smother the flames and interrupt the chemical reaction. Foam extinguishers can also be used on petroleum fires, but powder type (ABC dry chemical) is more versatile and commonly used.

Soaps are sodium or potassium salts of long-chain fatty acids (like stearic acid, palmitic acid). They are formed by saponification reaction where fats/oils react with alkali. They are not silicates, esters, or glycerol mixtures.

Traditional blue-black ink (iron gall ink) is prepared using ferrous sulphate along with gallic acid and tannic acid. These components react to form the dark-colored pigment. All three ingredients are essential for proper ink formulation.

Nylon is a polyamide because it contains amide bonds (-CO-NH-) linking the monomer units. Rayon is regenerated cellulose, Orion is a brand of acrylic, and Terylene is polyester (polyethylene terephthalate).

Carbon tetrachloride decomposes at high temperatures to form phosgene gas (COCl2), which is highly toxic. The question asks what gas is produced, and since phosgene is not listed as an option, the correct choice is 'None of these' - meaning the actual gas (phosgene) is not among the given choices.

Soaps are sodium or potassium salts of fatty acids, which are monocarboxylic acids (long-chain acids like stearic acid C17H35COOH have one carboxyl group). They are not salts of dicarboxylic or tricarboxylic acids.