
Lucas reagent is
(A) conc. HCl and anhydrous $ZnC{{l}_{2}}$
(B) conc. HCl and hydrous $ZnC{{l}_{2}}$
(C) conc. $HN{{O}_{3}}$ and hydrous $ZnC{{l}_{2}}$
(D) conc. $HN{{O}_{3}}$ and anhydrous $ZnC{{l}_{2}}$
Answer
445.2k+ views
Hint: 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 via an ${{S}_{N}}1$ reaction:
\[ROH+HCl\to RCl+{{H}_{2}}O\]
Complete step by step solution:
We have been asked about Lucas reagent,
Lucas' reagent is a solution of anhydrous zinc chloride in concentrated hydrochloric acid. This solution is used to classify alcohols of low molecular weight. The reaction is a substitution in which the chloride replaces a hydroxyl group.
So, we can say that: Lucas reagent is a mixture of conc. HCl and anhydrous $ZnC{{l}_{2}}$.
It is used to classify the low molecular weight alcohols into primary secondary and tertiary alcohols.
A primary alcohol is alcohol in which the hydroxy group is bonded to a primary carbon atom. It can also be defined as a molecule containing a $C{{H}_{2}}OH$ group. In contrast, secondary alcohol has a formula $CHROH$ and tertiary alcohol has a formula $C{{R}_{2}}OH$ where “R” indicates a carbon-containing group.
\[ROH+HCl\to RCl+{{H}_{2}}O\]
In this substitution reaction, hydroxide ion is replaced by chloride ion.
Therefore, we can conclude that option (A) is correct.
Note: Lucas’ reagent is a solution of zinc chloride in concentrated hydrochloric acid, used to classify alcohols of low molecular weight. Zinc chloride forms a complex with the oxygen of alcohol and converts the (-OH) to a much better-leaving group thereby giving way to a rapid formation of chloroalkane.
\[ROH+HCl\to RCl+{{H}_{2}}O\]
Complete step by step solution:
We have been asked about Lucas reagent,
Lucas' reagent is a solution of anhydrous zinc chloride in concentrated hydrochloric acid. This solution is used to classify alcohols of low molecular weight. The reaction is a substitution in which the chloride replaces a hydroxyl group.
So, we can say that: Lucas reagent is a mixture of conc. HCl and anhydrous $ZnC{{l}_{2}}$.
It is used to classify the low molecular weight alcohols into primary secondary and tertiary alcohols.
A primary alcohol is alcohol in which the hydroxy group is bonded to a primary carbon atom. It can also be defined as a molecule containing a $C{{H}_{2}}OH$ group. In contrast, secondary alcohol has a formula $CHROH$ and tertiary alcohol has a formula $C{{R}_{2}}OH$ where “R” indicates a carbon-containing group.
\[ROH+HCl\to RCl+{{H}_{2}}O\]
In this substitution reaction, hydroxide ion is replaced by chloride ion.
Therefore, we can conclude that option (A) is correct.
Note: Lucas’ reagent is a solution of zinc chloride in concentrated hydrochloric acid, used to classify alcohols of low molecular weight. Zinc chloride forms a complex with the oxygen of alcohol and converts the (-OH) to a much better-leaving group thereby giving way to a rapid formation of chloroalkane.
Recently Updated Pages
Master Class 12 Economics: Engaging Questions & Answers for Success

Master Class 12 Maths: Engaging Questions & Answers for Success

Master Class 12 Biology: Engaging Questions & Answers for Success

Master Class 12 Physics: Engaging Questions & Answers for Success

Master Class 12 Business Studies: Engaging Questions & Answers for Success

Master Class 12 English: Engaging Questions & Answers for Success

Trending doubts
The probability that a leap year will have only 52 class 12 maths CBSE

Describe the poetic devices used in the poem Aunt Jennifers class 12 english CBSE

And such too is the grandeur of the dooms We have imagined class 12 english CBSE

What does the god that failed refer to class 12 english CBSE

Which country did Danny Casey play for class 12 english CBSE

Draw a labelled sketch of the human eye class 12 physics CBSE
