Ethanol and methanol can be distinguished by a__________________?

A. Iodoform test
B. Lucas test
C. Benedicts test
D. Tollens test

¨       Ethanol and methanol can be distinguished by the Lucas test. The Lucas test is a simple test used to distinguish between primary, secondary, and tertiary alcohols. In this test, the alcohol is treated with an acidic solution of zinc chloride (Lucas reagent), which causes the alcohol to undergo a substitution reaction to form an alkyl chloride. The rate of reaction depends on the type of alcohol, with tertiary alcohols reacting the fastest, followed by secondary alcohols and primary alcohols. Methanol reacts very slowly or not at all, while ethanol reacts after a significant delay. Therefore, the Lucas test can be used to distinguish between ethanol and methanol, with ethanol giving a positive test and methanol giving a negative test.

 

¨       The Iodoform test is a test used to detect the presence of a methyl ketone or an alcohol that can be oxidized to a methyl ketone. In this test, the compound is treated with iodine and sodium hydroxide in the presence of water. If the compound is a methyl ketone or an alcohol that can be oxidized to a methyl ketone, it reacts with the iodine to form a yellow precipitate of iodoform.

 

¨       The Lucas test is a simple test used to distinguish between primary, secondary, and tertiary alcohols. In this test, the alcohol is treated with an acidic solution of zinc chloride (Lucas reagent), which causes the alcohol to undergo a substitution reaction to form an alkyl chloride. The rate of reaction depends on the type of alcohol, with tertiary alcohols reacting the fastest, followed by secondary alcohols and primary alcohols.

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¨       The Benedicts test is a test used to detect the presence of reducing sugars, such as glucose and fructose, in a solution. In this test, the sample is mixed with Benedict’s reagent, which contains copper sulfate, sodium carbonate, and sodium citrate. The mixture is then heated, causing the reducing sugars to react with the copper ions in the reagent to form a red-orange precipitate of copper oxide.

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¨       The Tollens test is a test used to detect the presence of an aldehyde. In this test, the sample is treated with Tollens’ reagent, which is a solution of silver nitrate and ammonia. The mixture is then heated, causing the aldehyde to reduce the silver ions in the reagent to form a silver mirror on the inside of the test tube or reaction vessel. This test is commonly used to detect the presence of glucose, which can be oxidized to form gluconic acid, a mild reducing agent that can reduce the silver ions to form the silver mirror.



Submitted by :- Jamil Ahmed

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