Q13.14 P - Chemistry: Molecular Nature Of Matter And Change

Question

Which member of each pair is more soluble in water? Why?

1. ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{OCH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{3}}\left(\mathbf{l}\right)\mathbf{ }\mathbf{or}\mathbf{ }{\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{OCH}}_{\mathbf{3}}\left(\mathbf{g}\right)$
   
2. ${\mathbf{CH}}_{\mathbf{2}}{\mathbf{Cl}}_{\mathbf{2}}\left(\mathbf{l}\right)\mathbf{ }\mathbf{or}\mathbf{ }\mathbf{ }{\mathbf{CCl}}_{\mathbf{4}}\mathbf{\left(}\mathbf{l}\mathbf{\right)}$
   
3. 
   

Step-by-Step Solution

Answer

1. ${\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{OCH}}_{\mathbf{2}}{\mathbf{CH}}_{\mathbf{3}}\left(\mathbf{l}\right)\mathbf{ }\mathbf{or}\mathbf{ }{\mathbf{CH}}_{\mathbf{3}}{\mathbf{CH}}_{\mathbf{2}}{\mathbf{OCH}}_{\mathbf{3}}\left(\mathbf{g}\right)$
   
2. ${\mathbf{CH}}_{\mathbf{2}}{\mathbf{Cl}}_{\mathbf{2}}\left(\mathbf{l}\right)\mathbf{ }\mathbf{or}\mathbf{ }\mathbf{ }{\mathbf{CCl}}_{\mathbf{4}}\mathbf{\left(}\mathbf{l}\mathbf{\right)}$ : There are no acidic hydrogens or electronegative atoms to form a strong H-bonding or ion-dipole interaction with water

3. Cyclohexane and tetrahydropyran: Though tetrahydropyran is soluble in water due to the presence of electronegative oxygen atom, cyclohexane is not soluble in water due to the absence of any acidic hydrogens or electronegative atoms. Therefore, this pair is not soluble in water.

Step 1: Definition of intermolecular force

In a solution, the intermolecular force is defined as the attractive force between the molecules of solute and solvent which is determined by the relative strength within and between the solute and the solvent. The solutes which have acidic hydrogens are more soluble in water to make a feasible hydrogen bond.

Step 2: Reason for solubility in water

It is due to the presence of an electronegative oxygen atom in diethyl ether and ethyl methyl ether which makes it   to form strong intermolecular H-bonding with solvent water.