Search results
Results From The WOW.Com Content Network
Linear alkylbenzenes (sometimes also known as LABs) are a family of organic compounds with the formula C 6 H 5 C n H 2n+1. Typically, n lies between 10 and 16, although generally supplied as a tighter cut, such as C 12 -C 15 , C 12 -C 13 and C 10 -C 13 , for detergent use. [ 1 ]
A calibration gas is a reference gas or gas mixture used as comparative standard in the calibration of analytical instruments, like gas analysers or gas detectors.Therefore, a calibration gas has to be of a precisely defined nature or composition, like zero gas or span gas, for example 500 ppm carbon monoxide in nitrogen.
In commercial applications, the alkylating agents are generally alkenes, some of the largest scale reactions practiced in industry.Such alkylations are of major industrial importance, e.g. for the production of ethylbenzene, the precursor to polystyrene, from benzene and ethylene and for the production of cumene from benzene and propene in cumene process:
*** Benzene is a carcinogen (cancer-causing agent). *** Very flammable. The pure material, and any solutions containing it, constitute a fire risk. Safe handling: Benzene should NOT be used at all unless no safer alternatives are available. If benzene must be used in an experiment, it should be handled at all stages in a fume cupboard.
Benzene targets the liver, kidney, lung, heart and brain and can cause DNA strand breaks and chromosomal damage, hence is teratogenic and mutagenic. Benzene causes cancer in animals including humans. Benzene has been shown to cause cancer in both sexes of multiple species of laboratory animals exposed via various routes. [83] [84]
The earliest recorded use of the internal standard method dates back to Gouy's flame spectroscopy work in 1877, where he used an internal standard to determine if the excitation in his flame was consistent. [3] [4] His experimental procedure was later reintroduced in the 1940s, when recording flame photometers became readily available. [3]
Formyl functional group is shown in blue. Formylation refers to any chemical processes in which a compound is functionalized with a formyl group (-CH=O). In organic chemistry, the term is most commonly used with regards to aromatic compounds (for example the conversion of benzene to benzaldehyde in the Gattermann–Koch reaction).
The term stems from cumene (isopropyl benzene), the intermediate material during the process. It was invented by R. Ūdris and P. Sergeyev in 1942 (USSR), [1] and independently by Heinrich Hock in 1944. [2] [3] This process converts two relatively cheap starting materials, benzene and propylene, into two more valuable ones, phenol and acetone.