Question

Rank the following organic compounds from most soluble in water to least soluble in water.
a.CH3OCH3
b.CH3CH3
c. CH3CH2OH

Answer 1

Concepts and reason

The solubility can be monitored by balancing the energies of intermolecular forces between the solute-solute, solute-solvent, solvent-solvent molecules. One simple empirical rule, polar molecules soluble in polar solvents (example: water, alcohols) and non-polar compounds dissolve in non-polar solvents (example: hexane, benzene).Generally, most of the organic compounds are relatively non-polar and insoluble in polar solvents like water. But the polar groups containing organic compounds are soluble in water.

Fundamentals

Solubility: At a given temperature, the maximum of amount solute that can be dissolved in a unit volume of solvent. Units are g/mL.

Factors affecting the solubility of organic compounds:

• Organic compounds containing polar are soluble in polar solvent and polarity of organic compounds can be determined by finding the polar bonds due to electronegativity atoms (example: N, O, F) in functional groups.

• If the hydrogen atom is directly attached electronegative atom exhibits the intermolecular hydrogen bonding. Due to this, solubility increases.

The order of solubility of organic compounds is given below:

Ans:

The order of solubility of organic compounds from most soluble in water to least soluble in water is given below:

$\,{\rm{c) C}}{{\rm{H}}_{\rm{3}}}{\rm{C}}{{\rm{H}}_{\rm{2}}}{\rm{OH}}\,\,{\bf{ > }}{\rm{ a)C}}{{\rm{H}}_{\rm{3}}}{\rm{OC}}{{\rm{H}}_{\rm{3}}}{\rm{ }}{\bf{ > }}{\rm{ b)C}}{{\rm{H}}_{\rm{3}}}{\rm{C}}{{\rm{H}}_{\rm{3}}}\,$