Answer
437.1k+ views
Hint: Victor Meyer's method is used to differentiate between the different types of alcohol. In this the alcohols are treated with different chemicals producing different colors, differentiating the alcohols.
Complete step by step answer:
-When an -OH group is attached to a hydrocarbon then it is known as an alcohol. Alcohols can be of three types: primary, secondary and tertiary alcohol.
-Primary alcohol is the one which is attached to the primary carbon atom of the hydrocarbon. Secondary alcohol is the one which is attached to the secondary carbon atom of the hydrocarbon. And tertiary alcohol is the one which is attached to the tertiary carbon atom of the hydrocarbon.
-A test or method known as Victor Meyer method is used to differentiate between primary, secondary and tertiary alcohols.
-In Victor Meyer's Method,
The given alcohol is made to react with conc. HI or red phosphorus and iodine to form the corresponding alkyl iodide.
-Then this produced alkyl iodide is treated with silver nitrate to produce the corresponding nitroalkane.
-This nitroalkane is then treated with nitrous acid which is $NaN{O}_{2} + {H}_{2}S{O}_{4}$ and then excess of caustic soda is added to make the solution alkaline.
-After this process, if a blood red color is obtained, then it indicates that the original reactant was a primary alcohol.
$\underset { Primary\quad alcohol }{ R-C{ H }_{ 2 }OH } \quad \xrightarrow [ P/{ I }_{ 2 } ]{ \quad } \quad R-C{ H }_{ 2 }I\quad \xrightarrow [ AgN{ O }_{ 2 } ]{ \quad } \quad R-C{ H }_{ 2 }N{ O }_{ 2 }\quad \xrightarrow [ HN{ O }_{ 2 } ]{ \quad } \quad \underset { Nitrolic\quad acid }{ R-C(NOH)-N{ O }_{ 2 } } \quad \xrightarrow [ NaOH ]{ \quad } \quad Blood\quad Red\quad Color$
- If a blue color is obtained, then it indicates that the original reactant was a secondary alcohol.
$\underset { Secondary\quad alcohol }{ { R }_{ 2 }-C{ H }OH } \quad \xrightarrow [ P/{ I }_{ 2 } ]{ \quad } \quad { R }_{ 2 }-CHI\quad \xrightarrow [ AgN{ O }_{ 2 } ]{ \quad } \quad { R }_{ 2 }-CHN{ O }_{ 2 }\quad \xrightarrow [ HN{ O }_{ 2 } ]{ \quad } \quad \underset { Pseudonitrol }{ { R }_{ 2 }-C(NO)-N{ O }_{ 2 } } \quad \xrightarrow [ NaOH ]{ \quad } \quad Blue\quad Color$
-If no color is obtained, then it indicates that the original reactant was a tertiary alcohol.
$\underset { Secondary\quad alcohol }{ { R }_{ 3 }-C-OH } \quad \xrightarrow [ P/{ I }_{ 2 } ]{ \quad } \quad { R }_{ 3 }-C-I\quad \xrightarrow [ AgN{ O }_{ 2 } ]{ \quad } \quad { R }_{ 3 }-C-N{ O }_{ 2 }\quad \xrightarrow [ HN{ O }_{ 2 } ]{ \quad } \quad No\quad Reaction\quad \xrightarrow [ NaOH ]{ \quad } \quad Colorless$
This is how Victor Meyer's method is used to differentiate between the three alcohols.
Note:
The Victor Meyer' test is only shown by primary, secondary and tertiary alcohols. It is not given by phenols. This is because in the first step R-OH is converted to R-I but the procedure involves breaking of the OH bond with carbon but in phenol as we know the carbon–oxygen bond is much stronger, and even the formation of the transition state will completely rupture the aromaticity this compound making the it unstable.
Complete step by step answer:
-When an -OH group is attached to a hydrocarbon then it is known as an alcohol. Alcohols can be of three types: primary, secondary and tertiary alcohol.
-Primary alcohol is the one which is attached to the primary carbon atom of the hydrocarbon. Secondary alcohol is the one which is attached to the secondary carbon atom of the hydrocarbon. And tertiary alcohol is the one which is attached to the tertiary carbon atom of the hydrocarbon.
-A test or method known as Victor Meyer method is used to differentiate between primary, secondary and tertiary alcohols.
-In Victor Meyer's Method,
The given alcohol is made to react with conc. HI or red phosphorus and iodine to form the corresponding alkyl iodide.
-Then this produced alkyl iodide is treated with silver nitrate to produce the corresponding nitroalkane.
-This nitroalkane is then treated with nitrous acid which is $NaN{O}_{2} + {H}_{2}S{O}_{4}$ and then excess of caustic soda is added to make the solution alkaline.
-After this process, if a blood red color is obtained, then it indicates that the original reactant was a primary alcohol.
$\underset { Primary\quad alcohol }{ R-C{ H }_{ 2 }OH } \quad \xrightarrow [ P/{ I }_{ 2 } ]{ \quad } \quad R-C{ H }_{ 2 }I\quad \xrightarrow [ AgN{ O }_{ 2 } ]{ \quad } \quad R-C{ H }_{ 2 }N{ O }_{ 2 }\quad \xrightarrow [ HN{ O }_{ 2 } ]{ \quad } \quad \underset { Nitrolic\quad acid }{ R-C(NOH)-N{ O }_{ 2 } } \quad \xrightarrow [ NaOH ]{ \quad } \quad Blood\quad Red\quad Color$
- If a blue color is obtained, then it indicates that the original reactant was a secondary alcohol.
$\underset { Secondary\quad alcohol }{ { R }_{ 2 }-C{ H }OH } \quad \xrightarrow [ P/{ I }_{ 2 } ]{ \quad } \quad { R }_{ 2 }-CHI\quad \xrightarrow [ AgN{ O }_{ 2 } ]{ \quad } \quad { R }_{ 2 }-CHN{ O }_{ 2 }\quad \xrightarrow [ HN{ O }_{ 2 } ]{ \quad } \quad \underset { Pseudonitrol }{ { R }_{ 2 }-C(NO)-N{ O }_{ 2 } } \quad \xrightarrow [ NaOH ]{ \quad } \quad Blue\quad Color$
-If no color is obtained, then it indicates that the original reactant was a tertiary alcohol.
$\underset { Secondary\quad alcohol }{ { R }_{ 3 }-C-OH } \quad \xrightarrow [ P/{ I }_{ 2 } ]{ \quad } \quad { R }_{ 3 }-C-I\quad \xrightarrow [ AgN{ O }_{ 2 } ]{ \quad } \quad { R }_{ 3 }-C-N{ O }_{ 2 }\quad \xrightarrow [ HN{ O }_{ 2 } ]{ \quad } \quad No\quad Reaction\quad \xrightarrow [ NaOH ]{ \quad } \quad Colorless$
This is how Victor Meyer's method is used to differentiate between the three alcohols.
Note:
The Victor Meyer' test is only shown by primary, secondary and tertiary alcohols. It is not given by phenols. This is because in the first step R-OH is converted to R-I but the procedure involves breaking of the OH bond with carbon but in phenol as we know the carbon–oxygen bond is much stronger, and even the formation of the transition state will completely rupture the aromaticity this compound making the it unstable.
Recently Updated Pages
Mark and label the given geoinformation on the outline class 11 social science CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
When people say No pun intended what does that mea class 8 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Name the states which share their boundary with Indias class 9 social science CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Give an account of the Northern Plains of India class 9 social science CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Change the following sentences into negative and interrogative class 10 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Advantages and disadvantages of science
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Trending doubts
Bimbisara was the founder of dynasty A Nanda B Haryanka class 6 social science CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Which are the Top 10 Largest Countries of the World?
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Differentiate between homogeneous and heterogeneous class 12 chemistry CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
10 examples of evaporation in daily life with explanations
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Fill the blanks with the suitable prepositions 1 The class 9 english CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Give 10 examples for herbs , shrubs , climbers , creepers
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
How do you graph the function fx 4x class 9 maths CBSE
![arrow-right](/cdn/images/seo-templates/arrow-right.png)
Difference Between Plant Cell and Animal Cell
![arrow-right](/cdn/images/seo-templates/arrow-right.png)