Web26 sep. 2011 · According to the method, coal tar is taken as a raw material; naphthalene is fractionated through a weight-removing column; firstly crude naphthalene is obtained; … Web19 mrt. 2024 · β-naphthalene sulfonic acid formaldehyde condensate is a kind of dispersant with good properties, such as wetting, emulsifying, dispersing. It is widely used as coating dispersant, dye dispersant ...
Naphthalene chemical compound Britannica
WebRecrystallization. Recrystallization, also known as fractional crystallization, is a procedure for purifying an impure compound in a solvent. The method of purification is based on the principle that the solubility of most solids increases with increased temperature. This means that as temperature increases, the amount of solute that can be ... A naphthalene molecule can be viewed as the fusion of a pair of benzene rings. (In organic chemistry, rings are fused if they share two or more atoms.) As such, naphthalene is classified as a benzenoid polycyclic aromatic hydrocarbon (PAH). The eight carbon atoms that are not shared by the two rings … Meer weergeven Naphthalene is an organic compound with formula C 10H 8. It is the simplest polycyclic aromatic hydrocarbon, and is a white crystalline solid with a characteristic odor that is detectable at concentrations as low as 0.08 Meer weergeven Reactions with electrophiles In electrophilic aromatic substitution reactions, naphthalene reacts more readily than benzene. For example, chlorination and bromination of naphthalene proceeds without a catalyst to give In terms of Meer weergeven Naphthalene is used mainly as a precursor to derivative chemicals. The single largest use of naphthalene is the industrial production of Meer weergeven • Camphor • Dialin, Tetralin, Decalin • List of interstellar and circumstellar molecules • Mothballs Meer weergeven In the early 1820s, two separate reports described a white solid with a pungent odor derived from the distillation of coal tar. In 1821, Meer weergeven Most naphthalene is derived from coal tar. From the 1960s until the 1990s, significant amounts of naphthalene were also produced from heavy petroleum fractions during petroleum refining, but present-day production is mainly from coal tar. Approximately … Meer weergeven Exposure to large amounts of naphthalene may damage or destroy red blood cells, most commonly in people with the inherited condition known as glucose-6-phosphate dehydrogenase (G6PD) deficiency Meer weergeven high low mint green prom dress
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WebThe naphtha is a mixture of many different hydrocarbon compounds. It has an initial boiling point(IBP) of about 35 °C and a final boiling point (FBP) of about 200 °C, and it contains paraffins, naphthenes(cyclic paraffins) and aromatic hydrocarbonsranging from those containing 4 carbonatomsto those containing about 10 or 11 carbon atoms. Web7 apr. 2024 · Place the sample into a slot in the MelTemp. Turn the dial to begin heating. Heat at a medium rate to 20oC below the expected melting point. Then heat very slowly ( 1oC every 30 seconds ). Record the temperature where the first droplet of liquid is seen (there is movement in the tube). WebNaphthalene is obtained from either coal tar or petroleum distillation and is primarily used to manufacture phthalic anhydride, but is also used in moth repellents. Exposure to naphthalene is associated with hemolytic … high low mother of groom dress