Transcript Slide 1
Introducing Alcohol http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0009891.html http://www.talktofrank.com/uploadedImages/Drugs/LARGE%20PHOTOS_ALCOHOL. jpg In chemistry, any member of a group of organic chemical compounds characterized by the presence of one or more aliphatic OH (hydroxyl) groups in the molecule, and which form esters with acids. The main uses of alcohols are as solvents for gums, resins, lacquers, and varnishes; in the making of dyes; for essential oils in perfumery; and for medical substances in pharmacy. The alcohol produced naturally in the fermentation process and consumed as part of alcoholic beverages is called ethanol. When consumed the effects of alcohol include poisoning at high concentrations, and changes in the functioning of human nerve cells. general formula Cn H2n+1 OH propanol methanol write their formulae and draw structures pentanol ethanol butanol hexanol highlighted items increase by CH2 http://cache.eb.com/eb/image?id=7388&rendTypeId=4 Discuss Any obvious trends in this data? http://cache.eb.com/eb/image?id=7388&rendTypeId=4 http://www.tiscali.co.uk/reference/encyclopaedia/hutchinson/m0009891.html Alcohols may be liquids or solids, according to the size and complexity of the molecule. A monohydric alcohol contains only one hydroxyl group in each molecule. The five simplest alcohols form a series in which the number of carbon and hydrogen atoms in the molecule increases progressively, each one having an extra CH2 (methylene) group: methanol or wood spirit (methyl alcohol, CH3OH); ethanol (ethyl alcohol, C2H5OH); propanol (propyl alcohol, C3H7OH); butanol (butyl alcohol, C4H9OH); and pentanol (amyl alcohol, C5H11OH). The lower alcohols are liquids that mix with water; the higher alcohols, such as pentanol, are oily liquids immiscible with water; and the highest are waxy solids – for example, hexadecanol (cetyl alcohol, C16H33OH) and melissyl alcohol (C30H61OH), which occur in sperm-whale oil and beeswax, respectively. Alcohols containing the CH2OH group are primary; those containing CHOH are secondary; while those containing COH are tertiary. Checked + correct, Mr G Functional group isomerism http://ehs.fullerton.edu/Safety4Students/images/IMAGE105.JPG 2-butanol 1-butanol http://home.att.net/~cat6a/images/Organicchem_40d.gif Functional group isomerism http://dl.clackamas.cc.or.us/ch106-03/nomenc3.gif 2-pentanol http://www.hamm-chemie.de/images/j11/strukturformeln/Alkanole/3-Pentanol.GIF 3-pentanol http://www.tennoji-h.oku.ed.jp/tennoji/oka/OCDB/HydrocarbonOxygen/3-pentanol-b.gif alcohol burning http://au.answers.yahoo.com/answers2/frontend.php/question?qid=20080403133339AA1YVt e combustion of alcohol C4H9OH CH3OH O2 CO2 H2O C2H5OH C3H7OH http://au.answers.yahoo.com/answers2/frontend.php/question?qid=20080403133339AA1YVt e combustion of alcohol C4H9OH CH3OH O2 CO2 H2O C2H5OH C3H7OH http://au.answers.yahoo.com/answers2/frontend.php/question?qid=20080403133339AA1YVt e sodium + alcohol C4H9OH Na CH3OH H2 C2H5OH C3H7OH ONa http://au.answers.yahoo.com/answers2/frontend.php/question?qid=20080403133339AA1YVt e sodium + alcohol C4H9OH Na CH3OH H2 C2H5OH C3H7OH ONa http://upload.wikimedia.org/wikipedia/commons/thumb/2/22/Ester.png/781pxEster.png acid + alcohol CH3OH CH3COOH C4H9OH HCOOH CH3COOC2H5 C2H5OH C3H7OH H2 O http://www.chemguide.co.uk/physical/catalysis/esterify.html The mechanism for the formation of ethyl ethanoate A reminder of the facts Ethanoic acid reacts with ethanol in the presence of concentrated sulphuric acid as a catalyst to produce the ester, ethyl ethanoate. The reaction is slow and reversible. To reduce the chances of the reverse reaction happening, the ester is distilled off as soon as it is formed. Notice, the acid OH group marked in green ends up as the free water molecule DO NOT LEARN THIS...TOO COMPLEX But its interesting! YES?