Question

Phenol is soluble in water because:
(A) It is a non polar compound
(B) It forms complex with water
(c) It forms hydrogen bond with water
(D)Phenol is not soluble in water

Answer 1

Hint: Phenol is an aromatic compound which contains a phenolic $–OH$ as a functional group so it can also be known as aromatic hydroxyl compound. The ability of a solute to dissolve in the solvent is known as solubility.

Complete step by step solution:
The phenol has a phenolic $–OH$ as a functional group. One of the hydrogens in hydrocarbon
($-C_6{H}_5$) is replaced by a hydroxyl group. The hydroxyl group is polar in nature as the electronegativity of oxygen is more than that of hydrogen to oxygen attracts hydrogen toward itself, therefore the hydrogen acquires a partial positive charge and oxygen acquires a partial negative charge. Likewise, water is also polar in nature as oxygen is more electronegative than hydrogen, so oxygen attracts two hydrogens towards itself and acquires partial negative charge and two hydrogen molecules acquire a partial positive charge on it. The polar substances are easily dissolved in water as polar solvents substances are hydrophilic in nature where hydro means water and philic means loving.
The hydrogen in hydroxyl groups forms intermolecular hydrogen bonds with water molecules.
Let’s look into options,
-Option A is “It is a nonpolar compound”. This option is wrong as phenol has a –OH group on it which is polar so phenol is a polar compound. Since water and phenol both are polar in nature therefore phenol is soluble in water. Thus this option is wrong.
-Option B is “It forms a complex with water”. Due to the presence of large hydrocarbon parts in phenol, it cannot form a complex with water. This option is incorrect.
-Option C is “It forms hydrogen bonds with water”. From the above discussion, it is evident that the hydroxyl group in phenol has the ability to form intermolecular hydrogen bonding with water. Thus option C is the correct option.
-Option D is “Phenol is not soluble in water”. Phenol is soluble in water as hydrogen in the hydroxyl group of phenol forms an intermolecular hydrogen bond with water molecules. Phenol is soluble in water. Thus this option is wrong.

Thus the correct option is (C).

Note: Phenol is soluble in water but up to an extent because of the presence of a large hydrocarbon group. So, we can conclude that phenol is soluble in water but up to an extent and solubility of phenol is due intermolecular hydrogen bond formed between hydrogen in hydroxyl group and water.