Hydrocarbons Alkynes Cycloalkanes

D Write, recognize, or otherwise identify (a) the structural unit, or functional group, (b) the general formula, and (c) the molecular or structural formulas and/or names of specific examples of the following classes of organic compounds alkanes, alkenes, alkynes, cycloalkanes, aromatic hydrocarbons, alcohols, ethers, aldehydes, ketones, carboxylic acids, esters, amines, and amides. 

Values for hydrocarbons other than alkynes and alkadienes can be predicted by the method of Suzuki et al. The best model includes the descriptors T, P, the parachor, the molecular surface area (which can be approximated by the van der Waals area), and the zero-order connectivity index. Excluding alkynes and alkadienes, a studv for 58 alkanes, aromatics, and cycloalkanes showed an average deviation from experimental values of about 30 K. 

Saturated hydrocarbons are stable. Only cycloalkanes with a tight ring are unstable. Alkenes and alkynes have a strong endothermic character, especially the first homologues and polyunsaturated conjugated hydrocarbons. This is also true for aromatic compounds, but this thermodynamic approach does not show up their real stability very well. Apart from a few special cases, the decomposition of unsaturated hydrocarbons requires extreme conditions, which are only encountered in the chemical industry. 

Solubility-Molar Volume Relationships The correlation between aqueous solubility at room temperature and the molar volume has been studied by McAuliffe [5] for different hydrocarbon classes. He discusses linear relationships, presented as graphs, describing the decrease in solubility with increasing molar volume for the homologous series of alkanes, alkenes, alkandienes, alkynes, and cycloalkanes. 

Hydrocarbons, R—Ha Alkanes CH3CH2CH3 propane Alkenes ch3ch=ch2 propene Alkynes ch3c=ch propyne Cycloalkanes ch2-ch2 /. ch2 ch2 / ch2-ch2 cyclohexane Arenes HC—CH // HC CH / HC CH benzene... 

You first should decide what type of compound it is. The decision usually is straightforward for hydrocarbons, which will fall in one or the other of the categories alkanes, alkenes, alkynes, arenes, cycloalkanes, and so on. But when the compound has more than one functional group it is not always obvious which is the parent function. For example, Compound 1 could be named as an alkene (because of the double-bond function) or as an alcohol (because of the OH function) ... 

In this section we shall consider the results recorded in the literature that pertain to the structures of the adsorbed species. Kinetic or catalytic aspects, as could be relevant to hydrogenation, hydrogenolysis, or metathesis processes, will be treated in Part 11. Spectra of the much-investigated alkenes are discussed in detail in Part I. The spectra of the other principal types of hydrocarbon adsorbates, viz. alkynes, alkanes, cycloalkanes, and aromatics, will be analyzed in Part II. Most results are available for the type-molecules ethene, ethyne, ethane, and benzene as well as for the metals, Pt, Pd, Ni, Rh, and Ru. 

As a complement to Table 2.4, size ratios of sH formers are shown in Table 2.7. Although many large sH formers are known, only alkanes and cycloalkanes are of interest, because alkenes and alkynes do not occur in natural hydrocarbons due to their reactivity. A large number of branched alkanes, including methyl butane, all polymethyl butanes, and a number of polymethyl pentanes form sH hydrates. 

Define or identify each of the following terms (a) organic chemistry, (b) total bond order, (c) condensed formula, (d) structural formula, (e) fine formula, (/) hydrocarbon, (g) alkane, (h) aUcene, (/) alkyne, j) aromatic hydrocarbon, (k) saturated, (1) delocalized double bond, (m) isomerism, (n) cycloalkane, (o) radical, (p) functional group, (q) alcohol, (r) ether, (s) aldehyde, (f) ketone, (u) carbonyl group, and (v) ester. 

Certain organic compounds contain only two elements, hydrogen and carbon, and hence are known as hydrocarbons. On the basis of structure, hydrocarbons are divided into two main classes, aliphatic and aromatic. Aliphatic hydrocarbons are further divided into families alkanes, alkenes, alkynes, and their cyclic analogs (cycloalkanes, etc.). We shall take up these families in the order given. 

The reactivity of alkanes and cycloalkanes are very low. Alkenes and alkynes containing double and triple bonds are reactive. The addition reactions follow Markovnikov rule. Conjugated dienes undergo Diels-Alder reactions. The substances that may react violently with unsaturated hydrocarbons are halogens, strong oxidizers, and nitrogen dioxide. Alkynes may form acetylides with certain metals. 

What structural features help us identify a compound as (a) an alkane, (b) a cycloalkane, (c) an alkene, (d) an alkyne, (e) a saturated hydrocarbon, (f) an aromatic hydrocarbon ... 

As compounds which consist of carbon and hydrogen atoms only, the hydrocarbons can be divided in two main categories, saturated, which comprises alkanes and cycloalkanes, and unsaturated, which comprises of alkenes, alkynes, and aromatics. The term saturated indicates the impossibihty of adding more hydrogens to the molecule. 

Hydrocarbons contain only C and H atoms, so their physical properties depend on the strength of their dispersion forces. The names of organic compounds have a root for the longest chain, a prefix for any attached group, and a suffix for the type of compound. Alkanes (CnHan+a) have only single bonds. Cycloalkanes (C Hp ) have ring structures that are typically nonplanar. Alkenes (CnHpn) have at least one C=C bond. Alkynes (CnHpn-p) have at least one C=C bond. Aromatic hydrocarbons have at least one planar ring with delocalized tt electrons. 

The hydrocarbon family includes alkanes (single covalent bonds), alkenes (double bonds), alkynes (triple bonds), cycloalkanes (contain a ring or cycle of carbons), and aromatics (contain at least one highly unsaturated six-carbon ring). 

Alkanes and cycloalkanes are saturated hydrocarbons. Methane, CH4, is the simplest of the alkanes, a family of hydrocarbons with the general formula C J32 +2. The cycloalkanes are a subfamily of alkanes whose carbon atoms are joined in a ring. Ethylene, CH2=CH2, is the simplest of alkenes, a class of hydrocarbons contaming carlx>n-carbon double bonds and having the general formula C H2 . Unsymmetrical alkenes ean exist as cis and trans isomers. Acetylene, CH=CH, is the simplest of the alkynes, which are compounds that have the general formula C H2 -2 and contain carbon-carbon triple... 

Unsaturated hydrocarbons (Section 2.12) Molecules containing It bonds. For example, alkenes or alkynes. This term does not include cycloalkanes. 

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