hydrocarbons_lab

hydrocarbons_lab - Hydrocarbons Dr Gergens SD Mesa College...

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Hydrocarbons Dr. Gergens - SD Mesa College Purpose: The hydrocarbons are a large class of compounds, but can be divided into subclasses based on structural features and reactivity. In this experiment, physical and chemical properties of a variety of saturated, unsaturated, and aromatic hydrocarbons standards will be analyzed. Finally, the chemical reac of alkanes, alkenens, and aromatics will be used to distinguish the subclass identity an unknown hydrocarbon sample. Physical Properties Reactivity of Hydrocarbons The sigma bonds of saturated hydrocarbons are very stable and hence very unreactive. Sometimes they are referred to as paraffins (with out affinity to re The pi bond on an mono-unsaturated hydrocarbon are reactive and undergo addition reactions. Bromine a brown li
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Procedure Part I Physical Properties A. Odors and Commercial Uses of Hydrocarbons Use chemfinder to determine each structure, melting and boiling point, synonyms, and commercial use for the compounds listed on the report data she Other handbooks and literature sources (Aldrich Chemical Catalog, Merck Index, CRC, et. may also be used. Correctly cite your reference sources. TEST Place about 10 drops of each hydrocarbon in three separate, clean dry test tubes. Smell the authentic samples of these compounds which the hood. Describe their odor on the report sheet. What do they smell like? Compare the odors of these hydrocarbons. CAUTION: Carefully waft va toward your nose. B. Solubility. Most organic compounds are not water soluble. Only low molecular weight and/or highly polar compounds will be water soluble to 3%. Salts of acids o will often be soluble. TEST Attempt to dissolve a 15 drops of each of the three compounds in 15 drops of water, 1-butanol, and ligroin. Hydrocarbons are neutr compounds and in water would not change water's pH. The words soluble and insoluble are qualitative, not quantitative. Sometimes the word miscible immiscible are used to describe solubility. If a compound is appreciably soluble in water it suggests that there are four or less carbons atoms for each ox or nitrogen atom. A ratio of five carbon atoms per oxygen or nitrogen usually gives borderline solubility or insolubility. If your compound is not comp soluble in water, you can call it insoluble or partially soluble in the solvent. Moreover, some compounds which are not soluble at room temperature, m soluble at higher temperature. Therefore, after obtaining data at room temperature, heat your solution in a hot water bath IN THE HOOD at 70 °C or high observe any further changes. The results you record may have more meaning later when you know more about your unknown compound.
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PART II Chemical Observations: A. Ignition Test. The ignition test consists of igniting a small sample of compound and observing the flame and smoke. Highly unsaturated comp especially aromatics, burn with a yellow flame and produce a sooty smoke. A yellow flame with non-sooty smoke indicates the presence of an alipha hydrocarbon. If oxygen is present in a compound, the flame appears more colorless (blue) because more complete combustion will chemically occur.
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hydrocarbons_lab - Hydrocarbons Dr Gergens SD Mesa College...

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