Alkanes general properties

Chemistry and general properties. The main challenge in the manufacture of paraffin sulphonates is the lack of a reactive function in the paraffin (alkane) hydrophobe but this is overcome by using the Strecker reaction or a variant of it. The classical Strecker reaction (shown in Figure 4.10) uses a chloroalkane (which can be made by the reaction of a chlorinating agent with an alcohol) and sodium sulphite. 

In the branched-chain alkanes (general formula C H2 +2), the carbon atoms are no longer arranged in a linear sequence, but instead can be bonded to three or four other carbon atoms. This possibility leads to a rich elaboration of structure in which two molecules with the same formula can have different structures, called geometrical isomers, and therefore quite distinct properties. 

Description and general properties. Methane [74-82-8], also called marsh gas, with the chemical formula CH, the relative molar mass of 16.04276 and a low density of 0.7168 kg.m under normal temperature and pressure conditions (273.15 K and 101.325 kPa), is the first and lightests member of the alkanes (i.e., saturated hydrocarbons or olefins with chemical formula C H2 2)- Methane is a colorless, odorless, non-poisonous and flammable gas that solidifies at -182.4°C (90.75 K) and boils under atmospheric pressure at -161.5°C (111.65 K). Methane is poorly soluble in water (e.g., 35 cm per kg of water at 17°C) but soluble in... 

Alkynes resemble alkanes and aUcenes m their physical properties They share with these other hydrocarbons the properties of low density and low water solubility They are slightly more polar and generally have slightly higher boiling points than the corre spondmg alkanes and alkenes... 

Aromaticity is the most important property of a carbon black feedstock. It is generally measured by the Bureau of Mines Correlation Index (BMCI) and is an indication of the carbon-to-hydrogen ratio. The sulfur content is limited to reduce corrosion, loss of yield, and sulfur in the product. It may be limited in certain locations for environmental reasons. The boiling range must be low enough so that it will be completely volatilized under furnace time—temperature conditions. Alkane insolubles or asphaltenes must be kept below critical levels in order to maintain product quaUty. Excessive asphaltene content results in a loss of reinforcement and poor treadwear in tire appHcations. 

J 6 Describe general trends in the physical properties of alkanes (Section 18.3). 

The choice of the solvent has a profound influence over the observed sonochemistry as well. The effect of vapor pressure has already been mentioned. Other liquid properties, such as surface tension and viscosity, will alter the threshold of cavitation (8), but this is generally a minor concern. The chemical reactivity of the solvent is often much more important. As discussed below, aqueous sonochemistry is dominated by secondary reactions of OH- and H- formed from the sonolysis of water vapor in the cavitation zone. No solvent is inert under the high temperature conditions of cavitation even linear alkanes will undergo pyrolytic-like cracking during high intensity sonication (89). One may minimize this... 

Alkanes of various types of crude oils and various petroleum products were biodegraded faster than the unresolved fractions. Different types of crude oils and products biodegraded at different rates in the same environments. An oil product is a complex mixture of organic chemicals and contains within it less persistent and more persistent fractions. The range between these two extremes is greatest for crude oils. Since the many different substances in petroleum have different physical and chemical properties, summarizing the fate of petroleum in general (or even a particular oil) is very difficult. Solubility-fate relationships must be considered. 

Alkanes, also called paraffins, are composed of all C-C, saturated bonds and have the general formula C H2n+2. The naming conventions and typical properties of the first... 

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