Alcohols and Carboxylic Acids AfL

1 Name:________________________________ Class:__________ Date:___________ AFL WORKSHEET Alcohols and Carboxylic Acids Structure of Alcohols 1. Alcohols are a homologous series of organic compounds which contains the ____________ functional group. 2. General molecular formula: _______________ (where n = 1, 2, 3 etc.) No. of carbon atoms Alcohol Molecular formula Full structural formula 1 CH3OH 2 ethanol 3 propanol C3H7OH 4

2 Properties of Alcohols 1. Alcohols are __________ liquids at room temperature and pressure. 2. Their boiling point ____________ down the series but their solubility ____________. 3. Alcohols burn in excess air to produce carbon dioxide and water vapour. E.g.: C2H5OH(aq) + 3O2(g) → ____________________ 4. Alcohols undergo oxidation to produce ____________________. An example of an oxidising agent is ______________________________. E.g.: C2H5OH(aq) + 2[O] heat  ____________________ Producing Ethanol 1. Ethanol can be produced from __________ by the catalytic addition of __________. Conditions: 300ºC, 60 atm, ____________________ catalyst C2H4(g) + H2O(g) 3 4 300 C, 60 atm H PO   C2H5OH(aq) 2. Ethanol can also be produced by ______________________________ in fruits, vegetables or grain. 3. _________________________ is a process in which micro-organisms such as yeast act on carbohydrates in the __________ of oxygen to produce ethanol and carbon dioxide gas. C6H12O6(aq) yeast  ____________________ 4. The enzymes in yeast work best at a temperature of about ______. Above this temperature, the enzymes are _____________ and fermentation stops. 5. Carbon dioxide and a __________ solution of ethanol are produced. If the alcohol content is higher than ______, the enzymes in the yeast will also die and cause fermentation to stop.

3 6. Ethanol is then extracted from the mixture by __________________________. 7. Fermentation of carbohydrates takes place only in the ________________________. Otherwise, the ethanol produced will be oxidised to ____________________. Uses of Ethanol 1. Ethanol can be used in alcoholic drinks, as a __________ and as a __________. Structure of Carboxylic Acids 1. Carboxylic acids are a homologous series of organic acids which contain the __________ __________ functional group. 2. General molecular formula: _______________ (where n = 0, 1, 2 etc.) No. of carbon atoms Carboxylic acid Molecular formula Full structural formula 1 2 ethanoic acid CH3COOH 3 C2H5COOH 4 butanoic acid

4 Properties of Carboxylic Acids Physical Properties of Carboxylic Acids 1. Carboxylic acids are very __________ in water. 2. Their boiling point ____________ with molecular size. Chemical Properties of Carboxylic Acids 1. Carboxylic acids are _______________ as they ionise partially in water. 2. They have acidic properties due to the _________________ produced. 3. They react with metals to produce a salt and _________________. E.g.: 2CH3COOH(aq) + Mg(s) → _______________________ 4. They react with carbonates to produce a salt, ______________________________. E.g.: 2CH3COOH(aq) + Na2CO3(s) → ______________________________ 5. They react with bases to produce a salt and __________. E.g.: CH3COOH(aq) + NaOH(aq) → _________________________ 6. They react with alcohols to produce ______________________________. Producing Ethanoic Acid 1. Ethanol can be ____________ into ethanoic acid by acidified potassium manganate(VII). As a result, acidified potassium manganate(VII) changes colour from __________ to __________. 2. Certain __________ in the air oxidise __________ to ethanoic acid. Thus, alcoholic drinks _______________ when left exposed to air for a few days.

5 Esters Esterification 1. Esters contain the __________ functional group. 2. An ester is formed when a carboxylic acid is warmed with an alcohol in the presence of a few drops of _________________________. The reaction is called _________________. carboxylic acid + alcohol concentrated sulfuric acid  ester + water E.g.: CH3COOH(aq) + C2H5OH(aq) 2 4concentrated H SO  _______________________ 3. Conditions for esterification: _________________________ catalyst, warming Naming Esters Alcohol Carboxylic acid Ester formed methanol methanoic acid methanol ethanoic acid ethanol methanoic acid ethanol ethanoic acid Uses of Esters 1. Esters have a sweet, fruity smell. Hence they are used in ____________ and as artificial food flavourings. 2. They are also used as solvents for _________________________ and in soaps.