ORGANIC CHEMISTRY REVISION PLACE MAT - https://www.tes.com/teaching-resource/vce-chemistry-revision-organic-chemistry-12042644
Reactions with alcohols
Alkanols
Ethanol is soluble in water as a consequence of its highly polar OH group. Alkanols undergo substitution. A common reaction is to oxidise the alkanol to form a carboxylic acid. Alcohols can be primary, secondary or tertiary. This means that the carbon that the –OH is attached to is: 1.Attached to one carbon (primary) 2.Attached to two carbons (secondary) 3.Attached to three carbon atoms (tertiary). Oxidation of primary alcohols -This gives an intermediate stage involving an aldehyde. (Diagram 1) Oxidation of secondary alcohols -This gives an intermediate stage involving a ketone. (Diagram 2) Oxidation of tertiary alcohols- does not occur since no extra hydrogen Combustion Alcohols burn to give carbon dioxide and water. C2H5OH (l) + 3O2(g)--- > 2CO2(g) + 3H2O(g) Alcohols such as ethanol can be used as fuel. |
Oxidation of a primary and secondary alcohol By MiPe (Own work) [CC BY-SA 4.0 (http://creativecommons.org/licenses/by-sa/4.0)], via Wikimedia Commons
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Carboxylic acids
•Functional group is -COOH
•Carboxylic acids names end in –oic acid.
•Example: ethanoic acid, CH3COOH
These are weak acids and they react slightly with water.
They also can react to form esters.
Esters
•Functional group is –COO-
•Esters are formed by a condensation reaction between a carboxylic acid and an alcohol.
•Uses: Give fruit their pleasant ‘fruity’ smell.
•EG: ethyl propanoate, CH3 CH2COOCH2CH3
An esterification reaction is the reaction in which an ester is made (reactions between a carboxylic acid and an alkanol.
Esters have two-part names- the first part derived from the name of the alcohol- yl replaces anol. The second part from the carboxylic acid- ic is replaced by ate.
Thus ethanol plus ethanioc acid will form ethyl ethanoate.
Hydrolysis of Esters
-the condensation reaction used to form esters is reversible.
Esters react with water (hydrolysis) to form a carboxylic acid and an alcohol.
Formation of amides
Carboxylic acid can react with ammonia or primary amines to form amides.
In these condensation reactions the –OH in the –COOH bond reacts with one of the -H’s attached in the ammonia or –NH2 to form water. The resulting carbon and nitrogen atoms will then bond together to form the amide.
•Carboxylic acids names end in –oic acid.
•Example: ethanoic acid, CH3COOH
These are weak acids and they react slightly with water.
They also can react to form esters.
Esters
•Functional group is –COO-
•Esters are formed by a condensation reaction between a carboxylic acid and an alcohol.
•Uses: Give fruit their pleasant ‘fruity’ smell.
•EG: ethyl propanoate, CH3 CH2COOCH2CH3
An esterification reaction is the reaction in which an ester is made (reactions between a carboxylic acid and an alkanol.
Esters have two-part names- the first part derived from the name of the alcohol- yl replaces anol. The second part from the carboxylic acid- ic is replaced by ate.
Thus ethanol plus ethanioc acid will form ethyl ethanoate.
Hydrolysis of Esters
-the condensation reaction used to form esters is reversible.
Esters react with water (hydrolysis) to form a carboxylic acid and an alcohol.
Formation of amides
Carboxylic acid can react with ammonia or primary amines to form amides.
In these condensation reactions the –OH in the –COOH bond reacts with one of the -H’s attached in the ammonia or –NH2 to form water. The resulting carbon and nitrogen atoms will then bond together to form the amide.