Isopropyl alcohol and n-propyl alcohol can be chemically distinguished by oxidation with potassium dichromate.n-propyl alcohol on oxidation with potassium dichromate gives an aldehyde. Isopropyl alcohol on oxidation with potassium dichromate gives a ketone. During oxidation of potassium dichromate, solution of potassium dichromate turns bluegreen in the reactions. For isopropyl alcohol this colour change is fast and for n-propyl alcohol the colour change is slow. 
Isopropyl alcohol and n-propyl alcohol are examples of position isomers.In isopropyl alcohol, the hydroxyl group is present in the second carbon atom whereas in n-propyl alcohol the hydroxyl group is present in the first carbon atom.