Question

Directions: Each question contains Statement- 1 and Statement- 2 and has the following choices (a), (b), (c) and (d), out of which ONLY ONE is correct. (a) Statement- 1 is True, Statement- 2 is True; Statement- 2 is a correct explanation for Statement- 1 (b) Statement- 1 is True, Statement- 2 is True; Statement- 2 is NOT a correct explanation for Statement- 1 (c) Statement- 1 is True, Statement- 2 is False (d) Statement- 1 is False, Statement- 2 is True Statement 1 Chloral forms a stable hydrate with water. and Statement 2 Chloral undergoes hydrolysis when heated with aqueous alkali to form chloroform.

Short answer

Answer: Both statements are true, but Statement 2 is NOT an explanation for Statement 1.

Step-by-step solution

Evaluate Statement 1

Chloral, also known as trichloroacetaldehyde (CCl3CHO), forms a stable hydrate with water (H2O). The reaction can be represented as: CCl3CHO + H2O -> CCl3CH(OH)2 This is a true statement. Chloral hydrate is a well-known chemical compound.

Evaluate Statement 2

When Chloral is heated with aqueous alkali, it undergoes hydrolysis to form chloroform (CHCl3) and a carboxylate ion. The reaction can be represented as: CCl3CHO + OH- -> CHCl3 + HCOO- This is also a true statement. Chloral reacts with alkali to form chloroform.

Determine if Statement 2 explains Statement 1

Though both Statement 1 and Statement 2 are true, Statement 2 doesn't explain the formation of a stable hydrate in Statement 1. Statement 2 simply describes a different reaction that involves heating the Chloral with an aqueous alkali, while Statement 1 is about the reaction of Chloral with water. Since both statements are true but Statement 2 is not an explanation for Statement 1, the correct answer is: (b) Statement- 1 is True, Statement- 2 is True; Statement- 2 is NOT a correct explanation for Statement- 1

Key concepts

Chloral Hydrate Formation

Understanding the formation of chloral hydrate is crucial for students studying organic chemistry, especially when preparing for competitive exams like the IIT JEE. Chloral hydrate is a geminal diol where two hydroxyl (-OH) groups are attached to the same carbon atom. It's formed when chloral (trichloroacetaldehyde) reacts with water. The reaction is showcased as:
\[ CCl_3CHO + H_2O \rightarrow CCl_3CH(OH)_2 \]
This process is significant in both industrial chemistry and pharmaceutical applications. Chloral hydrate itself is used as a sedative and a preservative for biological specimens. In an educational context, this reaction can serve as an example of how polarity and molecular structure affect chemical reactivity and stability of organic compounds.

Chloral Hydrolysis Reaction

The hydrolysis reaction of chloral is a transformation that must be distinguished from its hydration. When chloral is subjected to an aqueous alkali, it undergoes a hydrolysis reaction forming chloroform (CHCl_3) and a formate ion (HCOO^-). In a simplified form, the reaction looks like this:
\[ CCl_3CHO + OH^- \rightarrow CHCl_3 + HCOO^- \]
The importance of this mechanism lies in its application in the laboratory for the synthesis of chloroform, an organic solvent. Additionally, this reaction emphasizes the role of temperature and chemical environment in driving specific organic transformations, a key concept in reaction mechanisms in organic chemistry.

Organic Chemistry Reaction Mechanisms

Reaction mechanisms are the step-by-step pathways that lead from reactants to products in organic chemistry. Understanding these mechanisms is vital for students as they provide insight into the sequence of chemical transformations at the molecular level. These mechanisms involve the movement of electrons, the breaking and forming of chemical bonds, and the role of catalysts. Recognizing patterns such as nucleophilic substitutions or electrophilic additions and the stability of intermediates can empower students to predict the outcomes of reactions and to design new synthetic pathways. This knowledge is particularly essential for cracking challenging problems in exams like the IIT JEE.

Chemical Stability in Organic Compounds

The stability of organic compounds is influenced by several factors, including molecular structure, the presence of functional groups, and the external environment. Compounds like chloral hydrate are stable because the geminal diol formation creates strong intramolecular hydrogen bonds that stabilize the molecule. On the other hand, certain conditions or reagents can cause stable compounds to react further, as in the case of chloral's hydrolysis in the presence of aqueous alkali. Exploring these stability aspects not only helps students predict the reactivity and properties of organic molecules but also guides them in the storage and handling of chemicals in the lab.
Overall, comprehending the stability of organic compounds is a cornerstone in mastering organic chemistry and is a topic that features prominently in advanced exams, reflecting its real-world importance.