Carboxylic+acids

Carboxylic acids How To Spot A Carboxylic Acid

All carboxylic acids have the functional group -COOH. This is always attatched at the end of a carbon chain.
where R is the carbon chain

Caborxylic acids have two functional groups that we have seen before:

the carbonyl group, found in aldehydes and ketones and the hydroxyl group, -OH found in alcohols.

acids ||= R-COOH ||= ﻿-oic acid ||= Ethanoic Acid ||
 * = FAMILY ||= FORMULA ||= SUFFIX ||= EXAMPLE ||
 * = carboxylic

Aldehydes can be oxidised to form carboxylic acids﻿.  The most familiar carboxylic acid is ethanoic acid, which is the acid in vinegar. Other examples include:

 Naming Carboxylic Acids ﻿﻿To name carboxylic acids: 1) Find and name the longest alkane chain 2) ﻿Take off the 'e' 3) Add 'oic acid'  Ethanoic Acid

**<span style="color: #ff0000; font-family: Arial,Helvetica,sans-serif;">Physical Properties ** <span style="color: #fd0808; display: block; font-family: 'Arial Black',Gadget,sans-serif;"><span style="color: #000000; font-family: 'Arial Black',Gadget,sans-serif;">Carboxylic acids are polar. Because they are both hydrogen-bond acceptors (the carbonyl) and hydrogen-bond donors (the hydroxyl), they also participate in hydrogen bonding. They can form Hyrdogen bonds with water so Carboxylic acids up to Butanoic acid are completely solulbe in water.

Carboxylic acids can also form hydrogen bonds with each other when in a solid state, this causes them to have much higher melting points than the alkanes of similar MR, eg Ethanoic acid (Mr = 60) melts at 290K where as Butane (Mr = 58) melts at 136K. This property allows Carboxylic acids to be identified by measuring its melting point and comparing with a table of values of other melting points.

These acids also have characteristic smells, ie Ethanoic acid as vinegar and white butanoic acid causes butter to turn rancid. <span style="color: #fd0808; display: block; font-family: 'Arial Black',Gadget,sans-serif;"><span style="color: #000000; font-family: 'Arial Black',Gadget,sans-serif;"> The Reactions of Carboxylic Acids <span style="color: #000000; display: block; font-family: Arial,Helvetica,sans-serif;">﻿The carboxylic functional group is polarised. Below is a diagram showing how each atom is slightly charged: <span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">
 * <span style="color: #000000; display: block; font-family: Arial,Helvetica,sans-serif;">The carbon atom is open to attack from [|nucleophiles]
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">The 'O' atom may be attacked by positively charged species (like H+)
 * <span style="color: #000000; font-family: Arial,Helvetica,sans-serif;">The 'H' may be lost as H+ in which case the compound is behaving like an acid