Question

Amongst the following compounds, identify which are insoluble, partially soluble and highly soluble in water?

 (i) phenol

 (ii) toluene

 (iii) formic acid 

(iv) ethylene glycol

 (v) chloroform

(vi) pentanol.

Answer 1

(i) Phenol (C₆H₅OH) has the polar group −OH and non-polar group −C₆H_5. Thus, phenol is partially soluble in water. 

(ii) Toluene (C₆H₅−CH₃) has no polar groups. Thus, toluene is insoluble in water.

 (iii) Formic acid (HCOOH) has the polar group −OH and can form H-bond with water. Thus, formic acid is highly soluble in water. 

(iv)Ethylene glycol       has polar −OH group and can form H−bond. Thus, it is highly soluble in water. 

(v) Chloroform is insoluble in water. 

(vi)Pentanol (C₅H₁₁OH) has polar −OH group, but it also contains a very bulky nonpolar −C₅H₁₁ group. Thus, pentanol is partially soluble in water.