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Xam Idea Class 12 Chemistry Chapter 12 Solutions: Aldehydes, Ketones And Carboxylic Acids

Xam Idea Class 12 Chemistry Solutions Chapter 12 – Aldehydes, Ketones and Carboxylic Acids cover all the essential aspects of this chapter from organic chemistry. They follow the exact guidelines given by the CBSE board. Our Xam Idea Solution helps you to build a strong foundation for higher academic studies. They help you quickly and effectively grasp the topic of carbonyl compounds thoroughly and score good high marks in your Class 12 board exam.

This chapter explains the class of compounds known as aldehydes, ketones and carboxylic acids, their structures, IUPAC nomenclature, methods of preparation and reactions. This chapter also tells you how to correlate the structures of aldehydes, ketones and carboxylic acids with their physical and chemical properties and various aspects related to the acidity of carboxylic acids and their reactions. You learn about the uses of aldehydes, ketones and carboxylic acids also in this chapter.

Our Xam Idea Class 12 Chemistry Solutions Chapter 12 is divided into two major parts, namely Part A and Part B. Part A contains detailed explanations of the concepts covered in the chapter and the related questions. Our solutions cover all the types of questions given in the Xam Idea Book. Soe of the question types covered include multiple-choice questions, very-short answer, short answer, assertion reasoning type and long answer type questions. Part B of our solutions contains fully solved model test papers, sample question papers and NCERT questions.

Important Topics for Xam Idea Class 12 Chemistry Chapter 12 – Aldehydes, Ketones and Carboxylic Acids

Our Xam Idea Class 12 Chemistry Solutions Chapter 12 – Aldehydes, Ketones and Carboxylic Acids cover all the topics and subtopics of this chapter in details. They give you a comprehensive knowledge of the subject matter. The main concepts discussed in this chapter are as follows.

  • Nomenclature and Structure of Carbonyl Group

The chapter begins with the concepts that aldehydes and ketones are compounds containing a >C=O or ‘carbonyl’ group, which is polar. Rules guiding the nomenclature are given in this portion of the chapter. They can be named following any of two systems, namely, common names and IUPAC names. Here you will also learn that The C=O bond is polarised due to large electronegativity difference between oxygen and carbon and hybridisation in carbonyl carbon atom is sp2, and its structure is planar. 

Our Xam Idea Class 12 Chemistry Solutions Chapter 12 – Aldehydes, Ketones and Carboxylic Acids are comprehensive and yet contain to the point explanations of the topic to help you learn and revise quickly and efficiently during your exams.

  • Preparation of Aldehydes and Ketones

In this part of the chapter, you learn about all the methods of preparing aldehyde and ketone compounds. Aldehydes are prepared by controlled oxidation or dehydrogenation of primary alcohols, and ozonolysis of alkenes. Acyl halides can be selectively reduced to aldehydes in controlled conditions. If the reaction conditions are not controlled, the eventual products may be ketones or carboxylic acids.

Further, you learn that the aromatic aldehydes can be prepared by oxidising methylbenzene with chromyl chloride or CrO3 in the presence of (CH3CO)2O, formylation of arenes with CO and HCl in the presence of anhydrous AlCl2/Cu2Cl2, and by hydrolysis of benzal chloride.

This section also teaches you that ketones are prepared by oxidation of secondary alcohols and hydration of alkynes. Here you will also learn that ketones can also be prepared by ozonolysis of alkenes, the reaction of an acyl chloride with dialkylcadmium; and by Friedel Crafts acylation of aromatic hydrocarbons with acyl chlorides/anhydrides. Our Xam Idea Class 12 Chemistry Solutions Chapter 12 – Aldehydes, Ketones and Carboxylic Acids help you master the concepts of the same quickly and efficiently.

  • Physical Properties

The physical properties of aldehydes and ketones are guided by the presence of C=O polarised group. Here you learn that these compounds have high boiling points compared to hydrocarbons and weakly polar compounds of comparable molecular masses. The lower members are more soluble in water as they can form hydrogen bonds with water whereas for higher members, the large size of the hydrophobic chain of carbon atoms outweighs, and they become insoluble in water but they are soluble in common organic solvents.

  • Chemical Reactions

This part of the chapter teaches you that both the aldehydes and ketones similar types of chemical reactions because they contain the same functional group, carbonyl group. Both aldehydes and ketones undergo nucleophilic addition reactions at the carbonyl group with a number of nucleophilic reagents like alcohols, NH3, HCN, NaHSO3 and Grignard’s reagent.

Further, you learn here that α-hydrogens in aldehydes and ketones are acidic. Those aldehydes and ketones which have at least one α -hydrogen, undergo Aldol condensation, to give α – hydroxy aldehyde and α – hydroxy ketones respectively in basic conditions. Aldehydes which do not have an α-hydrogen give Cannizzaro reaction under similar conditions. Our Xam Idea Class 12 Chemistry Solutions Chapter 12 – Aldehydes, Ketones and Carboxylic Acids are drafted in simple and easy language, which makes the chapter much simpler.

Next, this chapter tells you that aldehydes and ketones undergo reduction with reducing agents like metal hydrides to give corresponding alcohols. They can also be reduced to alcohols by catalytic hydrogenation.  Here you will also learn that the carbonyl group of aldehydes and ketones can be reduced to a methylene group by Wolff-Kishner reduction and Clemmensen reduction. This sections also tells you that Aldehydes can be distinguished by using mild oxidising reagents like Tollen’s reagent or Fehling’s reagent. Aldehydes get oxidised to carboxylic acids whereas ketones are not with these reagents. Aldehydes and ketones find their use in several industries as solvents, starting materials and reagents.

  • Carboxylic acids

In this part, you learn that carboxylic acids are usually known by their common names. They can also be given IUPAC names following the prescribed nomenclature rules. The carboxylic carbon is less electrophilic than carbonyl carbon as there is a resonance between the two oxygen atoms of the carboxylic group. This section also tells you how Carboxylic acids are significantly acidic compared to alcohols and phenols. This is because the formation of the resonance stabilised carboxylate anion after losing proton.

Further, you will learn that carboxylic acids are prepared by oxidation of alkenes, aldehydes and primary alcohols. They are also prepared by hydrolysis of nitriles, and by treating Grignard reagents with CO2. Aromatic carboxylic acids are obtained when sidechains of alkylbenzenes are oxidised. Our Xam Idea Class 12 Chemistry Solutions Chapter 12 – Aldehydes, Ketones and Carboxylic Acids help you in gaining a better understanding of topics related to carboxylic acids with ease.

In this chapter, you will learn that Carboxylic acids undergo several chemical reactions. Reduction of carboxylic acids to primary alcohols is carried out with LiAlH4 or with B2H6 in ether solution. HVZ reaction is a characteristic reaction of carboxylic acids containing α-hydrogens. Here you will also learn that in this reaction, they undergo α-halogenation with halogens in the presence of red phosphorus. The carboxylic acids such as benzoic acid, formic acid and acetic acid are highly useful compounds in industry.

Exercise Discussion for Xam Idea Class 12 Chemistry Chapter 12 – Aldehydes, Ketones and Carboxylic Acids

This chapter comprises different types of questions such as very short answer (VSA), short answer (SA), and long answer questions (LA). Some other question types are multiple-choice questions, fill in the blank questions, match the following questions assertion-reasoning questions and direct questions. These questions test your remembering and understanding; higher-order thinking skills (HOTS); and application skills.

This chapter has 16 VSAQs which are based on IUPAC nomenclature, converting names into structures, predicting the product of the given reaction and drawing the structure of the product, Aldol and Cannizzaro reactions, arranging the compounds in increasing or decreasing order of given property, the acidity of carboxylic acids.

Next, there are 43 SAQs asking you to tell chemical terms and example of related reactions, distinguish between a pair of compounds through chemical tests, a direct question about describing the terms, predict the missing starting material, reagent or product, predict the intermediates and products in case of aldehydes, ketones and carboxylic acids.

Finally, there are 19 LAQs which are direct, explanatory and reason-based questions asking about predicting reagent, reactant or product of a chemical reaction. Some questions are based on characteristics of carbonyl group, preparation and properties of aldehydes, ketones and carboxylic acids, all the reactions shown by aldehydes and ketones, and reactions shown by carboxylic acids.

Apart from these questions given in part A of our solutions, there are several important NCERT questions and other questions of previous years’ examinations along with the model question papers, latest CBSE sample papers, previous year’s examination papers completely solved in Part – B of our solutions. It is advised to go through all these papers as well.

Benefits of Xam Idea Class 12 Chemistry Solutions Chapter 12 – Aldehydes, Ketones and Carboxylic Acids

Some of the major benefits of learning and revising from Xam Idea Class 12 Chemistry Solutions Chapter 12 – Aldehydes, Ketones and Carboxylic Acids are as follows –

  • These are user friendly, and you can learn from them anywhere anytime.
  • They help you build a strong conceptual foundation.
  • Our solutions provide best tips for remembering the named reactions related to aldehydes, ketones and carboxylic acids. 
  • They include detail explanations and relevant examples to help you learn efficiently.
  • They cover a wide range of question types important from exam point of view.
  • Our solutions help you score well in your Class 12 board exams.
  • They are framed in such a way that they make learning interesting, engaging, interactive and efficient.