What is the meaning of n in n-octane and similar compounds?
2014年8月6日 · This is somewhat of a holdover from the olden days, but in the case of octane in particular, it makes sense to specify n-octane if that is what you have. For example, the "octane" used as a standard gasoline engine fuel against which gasolines are rated (by definition, 100 octane) is actually not n -octane, but rather 2,2,4-trimethylpentane - a ...
nomenclature - What does "n" stand for in n-akyldiols, n-alkanes, …
2016年9月23日 · If we weren't dealing with n-alkanes we would have branched chain isomers to consider and potentially very different answers. It is old nomenclature from the days when adjacent carbons in a molecule were designated alpha,beta,gamma, etc and when acidity was given in 'N' units of normality." and " 'n' in science is like "x".
physical chemistry - Why is octane more volatile than water while ...
2023年10月5日 · There are indeed many isomers of octane. 2,2,4-trimethylpentane does have a boiling point of 99C, lower than water (while some other isomers, particularly n-octane, have a lot higher boiling point.) We should be sure we are comparing the same substance. Also, the per-mass latent heat of octane is indeed much lower than water.
Why do highly branched alkanes have higher octane numbers …
2018年7月12日 · The octane number of fuels are based on a set of primary reference fuels, which are mixtures of iso-octane and n-heptane. Now iso-octane being branched alkane has very less tendency to react and given ON=100 and n-heptane reacts easily and given ON=0. However n-octane that is the corresponding linear isomer of iso-octane has an ON<0. Now why ...
Is neo-octane possible and if yes, what is its structure?
2023年5月7日 · If you look at isomers of octane, you will see 4 of them have neo group out of which 2,2,4-Trimethylpentane has been commonly referred to as iso-octane although it contains both iso- and neo- group. Even if we eliminate isomers containing iso- group, we are left with 2,2-dimethylhexane and 2,2,3,3-dimethylbutane .
Stoichiometric calculations for the combustion of octane
2015年11月18日 · You have the ideal gas law (PV = nRT), and you know the P, the n from the first question, and the T - so just solve for the V. So you know one mole of $\ce{CO2}$ masses 44 grams, so just multiply this by the number of moles of $\ce{CO2}$ produced by 2 moles of octane (see my hint on point 1 above).
How is octane rating defined for negative values and those over …
2020年5月11日 · If, just illustratively, 100% isooctane had the critical compression ratio 1:20, 90% isooctane 1:19 ,... 90% n-heptane 1:11, 100% n-heptane 1:10, then the fuel with the critical compression ratio 1:21 would have the octane number 110. The octane number/rating differs for different procedures. See Research octane number RON, Motor octane number ...
physical chemistry - Density of saturated n-octane in air at 300 K ...
2019年6月15日 · For simplicity’s sake, we may assume that the gas phase (containing air and octane) is an ideal mixture of non-reacting gases and that the liquid phase contains only pure octane. Thus, for the calculation of parameter values for octane, we may ignore the air and only consider the equilibrium in a system of pure liquid octane and pure gaseous ...
enthalpy - Why are branched alkanes used as fuels instead of …
2020年9月4日 · For example, n-octane (the straight chain of 8 carbon atoms with no branching) has a -20 (negative) Research Octane Rating, whereas pure 2,2,4-trimethylpentane has an RON rating of 100. Some fuels have an octane rating higher than 100, notably those containing methanol or ethanol.
organic chemistry - What makes pentane, hexane, heptane, and …
Pentane, hexane, heptane, and octane are labelled with the ‘environment’ hazard pictogram (GHS09) since they are considered toxic or very toxic to aquatic life with long-lasting effects (H411 or H410) because of their toxicity to the water flea Daphnia magna in standardized tests.