Freezing Point Of Naphthalene

Freezing point of naphthalene I. Purpose To determine the firing point of known substances, naphthalene II. Material ring gas source test tube tube holder thermometer naphthalene lamp lamp goggle hose stopwatch III. Connect one end of the hose to the burner and connect the other end to the air supply device to program the Bunsen burner. The ring clamp is attached to the bracket that supports the tube, and the ring bracket is assembled so that the tube is used for experiments.

Naphthalene (also known as naphthalene, naphthalene, camphor pellets, tar camphor, white tar or white coal) is a crystalline aromatic white solid hydrocarbon, best known as the main component of camphor pills. Naphthalene is volatile and forms flammable vapors. Each molecule of this substance consists of two fused benzene rings. As its most abundant single component, it is obtained from coal tar and converted to phthalic anhydride for the production of plastics, dyes and solvents. It can also be used as a preservative and insecticide, especially in insect repellents (p-dichlorobenzene can be used instead of naphthalene as a camphor pill). Naphthalene easily sublimes at room temperature

The main use of naphthalene is to produce phthalic anhydride. However, as a preferred raw material for producing phthalic anhydride, o-xylene replaces naphthalene. (1) Other uses of naphthalene include carbamate insecticides, surfactants and resins, as dyes intermediates, as synthetic tanning agents, as anticaries agents, as various organic chemicals. (1,2) sources and potentially exposed individuals may be exposed to naphthalene by using camphor pills. (1) Workers may be exposed to naphthalene during occupation and manufacturing, especially in coal tar production, wood preservation, tanning or ink and dye production. (1) Naphthalene burns coal and oil and is released into the atmosphere using Mosball. Coal tar production, wood preservation and other industries release small quantities. (1) Typical atmospheric concentration of naphthalene in the city is about 0.18 ppb (ppb).

Naphthalene is the most abundant single component of coal tar. The composition of coal tar depends on the coal it produces, but the typical coal tar weighs about 10%. In industrial practice distillation coal tar produces oil containing about 50% naphthalene, and 12 other aromatic compounds. After washing the oily matter with an aqueous solution of sodium hydroxide to remove acidic components (mainly various phenols), the alkaline component was removed with sulfuric acid and fractionated to separate naphthalene. The crude naphthalene obtained in this way is about 95% naphthalene. The main impurities are sulfur-containing aromatic compounds benzothiophene (<2%), indane (0.2%), hydrazine (<2%), and methylnaphthalene (<2%). Petroleum derived naphthalene is generally more pure than naphthalene from coal tar. Production of approximately 1.3 million tons per year