The compound which reacts fastest with Lucas reagent at room temperatu...
The rates of reaction with lucas reagen t follows the order. 3° alcohol > 2° alcohol > 1° alcohol since carbocations are formed as intermediate, more stable the carbocation, higher will be the reactivity of the parent compound (alcohol). 2-Methylpropan-2-ol generates a 3º carbocation, so it will react fastest; other three generates either 1º or 2º carbocations.
2-Methyl-2-propanol
View all questions of this test
The compound which reacts fastest with Lucas reagent at room temperatu...
Reactivity of Alcohols with Lucas Reagent
The Lucas reagent is a mixture of concentrated hydrochloric acid and anhydrous zinc chloride, commonly used to test the reactivity of alcohols. The reaction involves the formation of alkyl chlorides from alcohols, with the rate of reaction depending on the nature of the alcohol.
Explanation:
2-Methylpropan-2-ol (tert-butanol)
- The fastest reaction with Lucas reagent at room temperature occurs with 2-Methylpropan-2-ol (tert-butanol).
- This is because tert-butanol is a tertiary alcohol, meaning that the carbon atom bearing the hydroxyl group is attached to three alkyl groups.
- Tertiary alcohols react the fastest with Lucas reagent due to the stabilization of the carbocation intermediate formed during the reaction.
Comparison with other options:
- Butan-1-ol and Butan-2-ol are primary alcohols, which react slower than tertiary alcohols with Lucas reagent.
- 2-Methyl propan-1-ol is a secondary alcohol, which also reacts slower than tertiary alcohols due to the less stable carbocation intermediate formed.
Conclusion:
- In summary, 2-Methylpropan-2-ol (tert-butanol) reacts the fastest with Lucas reagent at room temperature due to its tertiary nature, leading to the rapid formation of the alkyl chloride product.