 |
Business | Industries | Finance | Tax |
| Index: > A B C D E F G H I J K L M N O P Q R S T U V W X Y Z |
|
|||||
| First Prev [ 1 2 ] Next Last |
Naphthalene (also known as naphthalin, naphthaline, tar camphor, white tar, albocarbon, or naphthene) is a crystalline white solid hydrocarbon, with the empirical formula C10 H8. It is volatile, forming a flammable vapor. Its molecules consist of two benzene rings joined at one side. It is manufactured from coal tar, and converted to phthalic anhydride for the manufacture of plastics, dyes and solvents. It is also used as an antiseptic and insecticide, especially in mothballs.
A naphthalene molecule is composed of two fused benzene rings. (In organic chemistry, rings are fused if they share two or more atoms). Accordingly, naphthalene is classified as a benzenoid polycyclic aromatic hydrocarbon (PAH). Naphthalene has three resonance structures, which are shown in the above drawing. Naphthalene has two sets of equivalent hydrogens. The alpha positions are positions 1, 4, 5, and 8 on the above drawing. The beta positions are positions 2, 3, 6, and 7. The numbers 1-8 are used to
Like benzene, naphthalene can undergo electrophilic substitution. The major product generally has the electrophile in the "alpha" position. Sulfonation, however, gives a mixture of the "alpha" product 1-naphthalenesulfonic acid and the "beta" product 2-naphthalenesulfonic acid, with the ratio dependent on reaction conditions. Naphthalene can be hydrogenated to give tetralin, C10H18, also known as bicyclo[4.4.0]decane. Oxidation of naphthalene with chromate or permanganate , or catalytic oxidation with O2 and a vanadiumtitanium vanadium chromium V Nb Full table General Name, Symbol, Numbervanadium, V, 23 Chemical series transition metals Group, Period, Block 5, 4 , d Density, Hardness 6110 kg/m3, 7. 0 Appearance silvery grey metallic Atomic properties Atomic weight 50. catalystEnthalpy profile for catalysed and uncatalysed reactions. A is the activation energy for an uncatalysed reaction, A is the reduced activation energy for the same reaction when catalysed. I represents the point at which a chemical intermediate has been for, gives phthalic acid.
In humanHuman beings are defined variously in biological, spiritual, and cultural terms, or in combinations thereof. Biologically, they are classified as Homo sapiens ( Latin for knowing man , a primate species of mammal with a highly developed brain. In spirituas, exposure to large amounts of naphthalene may damage or destroy red blood cellRed blood cells are the most common type of blood cell and are the vertebrate body's principal means of delivering oxygen to body tissues via the blood. Red blood cells are also known as erythrocytes from Greek erythros for "red" and kytos for "hollow", ns. This could cause the body to have too few red blood cells until it replaces the destroyed cells. Humans, particularly children, have developed this condition after ingesting mothballs or deodorant blocks containing naphthalene. Some of the symptoms of this condition are fatigue, lack of appetite, restlessness, and pale skinThis article is about skin in the biological sense. For other uses of skin see skin (computing) and skinhead. Regarding exposure of the skin to be seen by others, or prevention of this, see nudity, nudism, modesty, clothing. Fruits such as oranges also ha. Exposure to large amounts of naphthalene may also cause nauseaNausea is the sensation of unease and discomfort from the stomach, with the sufferers feeling that they may vomit. Nausea is a symptom of many conditions, including motion sickness, morning sickness during pregnancy, viral infections, and other diseases., vomiting, diarrhea, blood in the urine, and a yellow color of the skin.
Animals sometimes develop cloudiness in their eyes after swallowing naphthalene. It is not clear if this also develops in humans.
When mice were repeatedly exposed to naphthalene vapors for two years, their noses and lungs became inflamed and irritated.
| Politics | Business | Finance |
 |
 |
 |
|