Question
Question: Are alcohols soluble in water?...
Are alcohols soluble in water?
Solution
Alcohols are a special group of compounds and are considered as a functional group in organic chemistry. In this functional group a hydroxyl group which is −OH is attached to a carbon atom. They are considered as polar because of the electronegativity difference between the oxygen atom and hydrogen atom.
Complete answer:
So, we know that alcohols are the functional group in which hydroxyl group is present. They are considered as polar in nature because of the electronegativity difference between the oxygen atom and hydrogen atom. It is attached to an alkyl chain.
Now, if we see a water molecule (H2O) , it is also polar in nature because of the electronegativity difference between the oxygen atom and hydrogen atoms and forms intermolecular hydrogen bonds. It does not contain any alkyl chain which is considered as hydrophobic in nature.
So, we know that, like, dissolves like. So polar compounds (alcohol) get dissolved in polar solvent (water) and hence, we can say that alcohols get dissolved in water.
As, we have discussed that the alkyl chain to which hydroxyl group is attached is hydrophobic (water repellent) in nature, so the lower members of alkyl alcohols are soluble in water but as the size of alkyl chain increases, its hydrophobic nature also increases. So, we can say that the higher members of alcohols are not much soluble in water.
Note:
In a water molecule, intermolecular hydrogen bonds are present and when it is reacted with alcohol the hydrogen bonds between the oxygen and hydrogen of water breaks down and new intermolecular hydrogen bonds are formed between the molecules of water and the alcohol as both of these contain the electronegative oxygen atom and a hydrogen atom.