WAEC - Chemistry (2019 - No. 30)
which of the following reagents could be used to distinguish between propan-1-ol and propan-2-ol
H+ / K2Cr2O7
I\(_2\) / OH-
CH\(_3\)COOH
NaCl
Explanation
when a primary alcohol like ethanol is warmed with excess of an oxidizing reagent, such as acidified Potassium permanganate( KMnO₄) or acidified Potassium dichromate(VI) ( K2Cr2O7 ), it is oxidized first to ethanal then to ethanoic acid, WHILE
Secondary alcohols like butan-2-ol will be oxidized to alkanones
propan-1-ol - primary alcohol,
propan-2-ol- secondary alcohol
- The Lucas test in alcohols is a test to differentiate between primary, secondary, and tertiary alcohols. It is based on the difference in reactivity of the three classes of alcohols with hydrogen halides