ArCOOH ArCHOH ArCOONH2 Aldehydes may be prepared by oxidation of primary alcohols Lu 0 IFTT Gl; By heating Carboxylic acid with primary or secondary alcohol in the presence of a small amount of metallic acid, an ester and water will be formed Esters Carboxylic acid Alcohol
The Correct Answer and Explanation is:
Here are the correct answers for the chemistry questions presented in the image, followed by a detailed explanation.
- RCHO
- Ar COOH
- T (True)
- Esters
Explanation
- The first question relates to the oxidation of a primary alcohol (RCH2OH) with an oxidizing agent like sodium dichromate (Na2Cr2O7). This is a common reaction in organic chemistry. When a primary alcohol is oxidized under controlled conditions (for example, by distilling the product as it forms), the product is an aldehyde, which has the general formula RCHO. If the reaction is not controlled, the aldehyde will be further oxidized to a carboxylic acid. Among the choices provided, the aldehyde is the correct initial product.
- The second question illustrates the reaction of a Grignard reagent (Ar Mg X) with carbon dioxide (CO2). This process is known as carboxylation and is a standard method for synthesizing carboxylic acids. The highly nucleophilic carbon atom of the Grignard reagent attacks the electrophilic carbon of carbon dioxide. After this addition, an acidic workup (protonation) is performed to produce the final product, which is an aromatic carboxylic acid, Ar COOH.
- The statement “Aldehydes may be prepared by oxidation of primary alcohols” is True. This is a fundamental concept in organic synthesis. As described in the first point, the oxidation of primary alcohols is a key route to producing aldehydes. Specific reagents, such as pyridinium chlorochromate (PCC), are often used to achieve this transformation cleanly without over-oxidation.
- The final question describes Fischer esterification. This reaction involves heating a carboxylic acid with an alcohol in the presence of an acid catalyst (the image has a typo, “ametallic acid,” which should be “a mineral acid” like sulfuric acid). The question itself states that “an ester and water will formed.” Therefore, the class of organic compounds produced in this reaction is Esters.
