Paraffins

the general term for the ALKANES, saturated ALIPHATIC HYDROCARBONS with the formula C_nH_2n+2. They are quite unreactive hence the name paraffin (from the Latin parum affinis, little allied).

Taken from Dictionary of Science

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In chemistry, paraffin is the common name for the alkane hydrocarbons with the general formula C_nH_2n+2. Paraffin wax refers to the solids with 20 ≤ n ≤ 40 .

The simplest paraffin molecule is that of methane, CH₄, a gas at room temperature. Heavier members of the series, such as that of octane, C₈H₁₈, and mineral oil appear as liquids at room temperature. The solid forms of paraffin, called paraffin wax, are from the heaviest molecules from C₂₀H₄₂ to C₄₀H₈₂. Paraffin wax was identified by Carl Reichenbach in 1830.

Paraffin, or paraffin hydrocarbon, is also the technical name for an alkane in general, but in most cases it refers specifically to a linear, or normal alkane — whereas branched, or isoalkanes are also called isoparaffins. It is distinct from the fuel known in Ireland, Britain and South Africa as paraffin oil or just paraffin, which is called kerosene in most of the U.S., Canada, Australia and New Zealand.

The name is derived from the Latin parum (= barely) + affinis with the meaning here of "lacking affinity", or "lacking reactivity". This is because alkanes, being non-polar and lacking in functional groups, are very unreactive.

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Acetic Acid

a chemical compound, more correctly called ethanoic acid, which is the acid found in vinegar. It is present as a solution in water of strength 3 to 6%, in other words there are 3 to 6 parts of acetic acid in 100 parts of water. The chemical formula for acetic acid is CH₃COOH which contains two carbon atoms bonded together; to one are bonded three hydrogen atoms and to the other one one oxygen and one hydroxyl group (OH). Acetic acid is made from ethanol or acetylene.

Taken from Dictionary of Science

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Acetic acid, CH₃COOH, also known as ethanoic acid, is an organic acid, which gives vinegar its sour taste and pungent smell. It is a weak acid, in that it is only a partially dissociated acid in an aqueous solution. Pure, water-free acetic acid (glacial acetic acid) is a colourless liquid that absorbs water from the environment (hygroscopy), and freezes at 16.5 °C (62 °F) to a colourless crystalline solid. The pure acid, and concentrated solutions, are dangerously corrosive.

Acetic acid is one of the simplest carboxylic acids. It is an important chemical reagent and industrial chemical, used in the production of polyethylene terephthalate mainly used in soft drink bottles; cellulose acetate, mainly for photographic film; and polyvinyl acetate for wood glue, as well as synthetic fibres and fabrics. In households, diluted acetic acid is often used in descaling agents. In the food industry acetic acid is used under the food additive code E260 as an acidity regulator and as a condiment on chips.

The global demand of acetic acid is around 6.5 million tonnes per year (Mt/a), of which approximately 1.5 Mt/a is met by recycling; the remainder is manufactured from petrochemical feedstocks or from biological sources. Dilute acetic acid produced by natural fermentation is called vinegar.

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Young's Modulus

Young's modulus (E) relates the STRESS and STRAIN in a solid (usually wire) using the following formula:

E = stress/strain = σ/ε

where σ = Force/Area and E = Change in Length/Length

Young's modulus has units of newtons per metre squared (Nm^-2) and is calculated only when the material is under elastic conditions, i.e., the force applied does not exceed the elastic limit and cause deformation.

Taken from Dictionary of Science

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In solid mechanics, Young's modulus (E) is a measure of the stiffness of an isotropic elastic material. It is also known as the Young modulus, modulus of elasticity, elastic modulus (though Young's modulus is actually one of several elastic moduli such as the bulk modulus and the shear modulus) or tensile modulus. It is defined as the ratio of the uniaxial stress over the uniaxial strain in the range of stress in which Hooke's Law holds. This can be experimentally determined from the slope of a stress-strain curve created during tensile tests conducted on a sample of the material.

Young's modulus is named after Thomas Young, the 19th century British scientist. However, the concept was developed in 1727 by Leonhard Euler, and the first experiments that used the concept of Young's modulus in its current form were performed by the Italian scientist Giordano Riccati in 1782 — predating Young's work by 25 years.

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Naphthalene

consists of two BENZENE rings joined together (with the loss of some carbon and hydrogen--condensed) to give the formula C₁₀H₈. It is a white crystalline solid and is obtained from COAL TAR (in the fraction, or part, boiling between 180°C and 200°C) and from PETROLEUM fractions, by demethylation i.e. the removal of the METHYL group from methylnaphthalene. Naphthalene is more reactive than benzene and it is used mostly in the production of plasticizers and resins. Some derivatives of naphthalene are important in the manufacture of dyestuffs.

Taken from Dictionary of Science

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Naphthalene, also known as naphthalin, bicyclo[4.4.0]deca-1,3,5,7,9-pentene or antimite and not to be confused with naphtha, is a crystalline, aromatic, white, solid hydrocarbon with formula C₁₀H₈ and the structure of two fused benzene rings. It is best known as the traditional, primary ingredient of mothballs. It is volatile, forming an inflammable vapor, and readily sublimes at room temperature, producing a characteristic odor that is detectable at concentrations as low as 0.08 ppm by mass.

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Calcium Carbonate

a common chemical compound in nature with the formula CaCo3. In the form of calcite, it is an abundant MINERAL in rocks especially LIMESTONE, CHALK and MARBLE. It is used by man in the manufacture of cement and fertilizer.

Taken from Dictionary of Science

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Calcium carbonate is a chemical compound with the chemical formula CaCO₃. It is a common substance found in rock in all parts of the world, and is the main component of shells of marine organisms, snails, pearls, and eggshells. Calcium carbonate is the active ingredient in agricultural lime, and is usually the principal cause of hard water. It is commonly used medicinally as a calcium supplement or as an antacid, but excessive consumption can be hazardous.

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