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
Water is a polar compound (due to electronegativity difference between O and H) . We know that “like dissolves like”. So, a non-polar compound will be more soluble in non-polar solvent as compared to polar compound.
(i) Phenol has the polar group -OH and non-polar group –C6H5 and it can not form H bonding with water(presence of bulky non-polar group) . Thus, phenol is partially soluble in water.
(ii) Toluene 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(OH-CH2-CH2-OH) has polar -OH group and can form H-bond with water. Thus, it is highly soluble in water.
(v) Chloroform is partly soluble as CHCl3 is polar in nature due to high electronegativity of Cl atoms, there will be production of partial + charge on H atom so it can form H bonding with water but it is also surrounded by 3 Cl atoms, so partly soluble.
(vi) Pentanol(C5H11OH) has polar -OH group, but it also contains a very bulky non-polar group –C5H11. Thus, pentanol is partially soluble in water.