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Pentane is an organic compound with the formula C 5 H 12 —that is, an alkane with five carbon atoms. The term may refer to any of three structural isomers, or to a mixture of them: in the IUPAC nomenclature, however, pentane means exclusively the n-pentane isomer, in which case pentanes refers to a mixture of them; the other two are called isopentane (methylbutane) and neopentane ...
2 (C 2 H 5). Isopentane is a volatile and flammable liquid. It is one of three structural isomers with the molecular formula C 5 H 12, the others being pentane (n-pentane) and neopentane (2,2-dimethylpropane). Isopentane is commonly used in conjunction with liquid nitrogen to achieve a liquid bath temperature of −160 °C.
Boiling-point elevation is the phenomenon whereby the boiling point of a liquid (a solvent) will be higher when another compound is added, meaning that a solution has a higher boiling point than a pure solvent. This happens whenever a non-volatile solute, such as a salt, is added to a pure solvent, such as water.
As a rule of thumb, the boiling point rises 20–30 °C for each carbon added to the chain; this rule applies to other homologous series. [18] A straight-chain alkane will have a boiling point higher than a branched-chain alkane due to the greater surface area in contact, and thus greater van der Waals forces, between adjacent molecules.
Boiling point (°C) K b (°C⋅kg/mol) Freezing point (°C) ... 2.79 6.55 –20.2 Diethyl ether: 0.713 34.5 ... 55.2 [17] Pentane: 36.1 [18] Petroleum Ether: 35.0-60.0
For example, ethane (C 2 H 6), has a higher boiling point than methane (CH 4). This is because the London dispersion forces between ethane molecules are higher than that between methane molecules, resulting in stronger forces of intermolecular attraction, raising the boiling point.
Different zeotropic mixtures have different temperature glides. For example, zeotropic mixture R152a/R245fa has a higher temperature glide than R21/R245fa. [7] A larger gap between the boiling points creates a larger temperature glide between the boiling curve and dew curve at a given mass fraction. [4]
Water boiling at 99.3 °C (210.8 °F) at 215 m (705 ft) elevation. The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid [1] [2] and the liquid changes into a vapor.