Question

Which of the following gases is expected to be most soluble in water? Explain your reasoning.

(a) \({\bf{CH}}_4\)

(b) \({\bf{CCl}}_4\)

(c)\({\bf{CHCl}}_3\)

Short answer

\({\rm{CHCl_3}}\) is expected to be most soluble in water. In this, the only polar molecule which dissolves in a polar solvent like water is \({\rm{CHCl_3}}\).

Step-by-step solution

Solubility

Solubility is the amount of a solute that can dissolve into solvent and form a solution that could or could not conduct electricity.

As we all know, “like dissolves like”. According to this statement, the polar substances dissolve with polar and non-polar substances dissolve with non-polar.

(a) Explanation on polarity for \({\bf{CH_4}}\)

\({\rm{CH_4}}\) (methane) is an organic compound, which is less polar than \({\rm{CHCl_3}}\) as their dipole moment is zero.

(b) Explanation on polarity for \({\bf{CCl_4}}\)

Carbon tetrachloride is non-polar in nature. That’s why it will have less solubility in water as compared to \({\rm{CHCl_3}}\).

(c) Explanation on polarity for \({\bf{CHCl_3}}\)

\({\rm{CHCl_3}}\) is expected to be most soluble in water because of the formation of dipole-dipole interaction as both \({\rm{CHCl_3}}\) and water are polar in nature. Of the three gases, only \({\rm{CHCl_3}}\)is polar.