Alcohols and organic analysis GapFill

Alcohols contain the functional group   OHCHOR(C=O)RNH2. They are often manufactured industrially by reacting  alkenes with steamhalogenoalkanes with steamalkenes with sodium hydroxidehalogenoalkanes with sodium hydroxide in the presence of an acid catalyst. Ethanol can be produced by an alternative method:  photosynthesistranspirationgerminationfermentation. Here, yeast synthesises the alcohol from the  chlorophylllonger alcoholsethaneglucose present in plants. Ethanol can be used as a fuel, as well as in drinks; fuels derived from plant matter or organic waste are called  phytofuelsbiofuelsdetritifuelsbotanifuels.

Alcohols can be oxidised by heating with acidified potassium  dichrominedichromatedichromidedichromane(VI), K₂Cr₂O₇, solution, which is often represented in equations by [O]. Primary alcohols can be either partially oxidised to aldehydes, which have the functional group   CHOC=CCOOHCONH2, or fully oxidised to carboxylic acids, which have the functional group  C=COHCOOHCONH2. The extent of oxidation can be controlled by changing the experimental set-up. If the aldehyde is immediately distilled from the reaction mixture, it will not be oxidised further; if the reaction mixture is heated under   reflexrefixreflowreflux, the major product will be a carboxylic acid. Secondary alcohols can be oxidised to ketones, which have the functional group   CONH2COOHOHR(C=O)R . Tertiary alcohols cannot be oxidised.

In the mass spectrum of an organic molecule, the peak with the highest m/z value is caused by the   primarymolecularfundamentalabsolute ion, which is identical to the original molecule, except that it is missing an electron. Another common technique in organic analysis relies on the absorption of light at different frequencies by different bonds; it is called   X-raymicrowaveradioinfrared spectroscopy as all the frequencies absorbed lie in this section of the electromagnetic spectrum. (The bonds in atmospheric carbon dioxide, methane and water vapour absorb this type of radiation particularly efficiently, leading to global warming. These molecules are called  insulantradiativeblanketgreenhouse gases.) In this kind of spectroscopy, the x-axis of the spectrum shows the frequency of light, measured in   wave crestswave cycleswave numberswave peaks (cm⁻¹). The y-axis shows the percentage of the light that is transmitted (i.e. not absorbed). The region of the spectrum below 1500 cm⁻¹ is known as the  fingerprintcharacteristichallmarkdiagnostic region; it is unique to a given organic molecule, and can be compared to a database of many spectra in order to identify the molecule.