NCERT

Chapter 10 Biomolecules of Class 12 Chemistry includes several important topics which are frequently asked in the state and cbses board exams. The most important topics in the Biomolecules chapter include the classification and structure of carbohydrates (monosaccharides, disaccharides, polysaccharides), amino acids and proteins (including peptide bond formation), enzymes and their characteristics, nucleic acids (DNA and RNA structure and components), and vitamins with their types and deficiencies.

Questions often focus on structural identification, naming, and functions of biomolecules, as well as simple reactions like hydrolysis and oxidation. Students should also pay attention to zwitterion structure in amino acids, enzyme action mechanisms, and differences between DNA and RNA. Students must practice diagrams and learn key functions of each biomolecule to score full marks in this chapter. Students can take help of NCERT Solutioins for Class 12 Chemistry Biomolecules to get good understanding of the concepts and requirements.

Biomolecules are organic compounds essential to life, found in all living organisms. Biomolecules include carbohydrates, proteins, lipids, nucleic acids, enzymes, and vitamins.

NCERT Class 12 Chemistry chapter 10 Biomolecules covers the molecular basis of life, including the structure, types, and functions of each biomolecule. This chapter is important because it connects chemistry to biology and helps students understand metabolism, heredity, and biochemical reactions. It also forms the foundation for higher studies in medicine, biochemistry, and biotechnology. Biomolecules are also frequently tested in CBSE board exams and competitive exams like NEET and JEE, making it a crucial topic to master.

Amines are prepared by replacing the hydrogen atom with alkyl or aryl groups from amonia (NH? ). Students can differntiate Aliphatic and aromatic amines differ based on the type of group attached to the nitrogen atom. 

• Aliphatic amines have one or more alkyl groups (like methyl or ethyl) bonded to the nitrogen, such as ethylamine (CH? NH? ). 
• Aromatic amines have an aryl group (like benzene) directly bonded to nitrogen, for example, aniline (C? H? NH? ).

Aliphatic amines are generally more basic than aromatic amines because, in aromatic amines, the lone pair on nitrogen is delocalized into the aromatic ring through resonance, reducing its availability for protonation. This structural difference affects their chemical reactivity, basicity, and physical properties.

According to the NCERT Solutions for Class 11 Physics Chapter 8 Mechanical Properties of Solids, when an external force is applied to a solid, the solid undergoes changes in shape or size which is called deformation. The solid deformation can be classified into:

Elastic Deformation: It is when the body returns to its original size and shape after the force is removed. It occurs within the elastic limit and follows Hooke's law. The most common examples include stretching a helical spring or a rubber band.

Plastic Deformation: It occurs beyond the elastic limit and here after the removal of the force, the body does not return to its original shape and size. Hence, the force applied leads to the permanent deformation of the solid. Common examples include deformation in putty, clay or bending of a metal wire beyond a certain limit.

The plastic deformation is irreversible and elastic deformation is reversible. These concepts are important when studying engineering, material science, and construction.

The modulus of elasticity refers to the material's capacity to withstand or resist deformation when stress is applied. There are three types of the modulus of elasticity including:

Young's Modulus (E): It is used to measure a solid's elasticity when longitudinal stress (tensile or compressive) is applied to it. Mathematically, it is represented by the following formula;

SI Unit is N/m² (Pascal, Pa).

Bulk Modulus (K): It is used to measure the ability of the material to resist volume change when uniform pressure is applied to it. Mathematically, it is:

SI Unit is N/m² (Pa)

Shear Modulus (G) or Modulus of Rigidity: It is used when a shear force is applied to measure the resistance to shape change. Mathematically, it is represented by:

SI Unit: N/m² (Pa)

The value of each modulus varies for different materials, and it describes different types of deformation.

Students can check Class 12 Chemistry Chapter 9 Amines NCERT Solutions, which can help you know name chemical reactions crucial for CBSE Board Exams and Competitive Exams like JEE and NEET:

• Gabriel Phthalimide Synthesis – Used to prepare primary amines from phthalimide via hydrolysis.

• Hoffmann Bromamide Degradation Reaction – Converts amides to primary amines with one less carbon atom using Br? and NaOH.

• Carbylamine Reaction – A test for primary amines where they react with chloroform and KOH to form isocyanides (foul-smelling).

• Acylation and Alkylation of Amines – Involves the reaction of amines with acid chlorides or alkyl halides.

• Coupling Reaction – Aryldiazonium salts react with phenols or aromatic amines to form azo dyes.

The chapter consists of fundamental topics that are important for board exams preparation as well as for competitive tests: 

• Composition and Size of the Nucleus: Understanding protons, neutrons, and nuclear density.

• Nuclear Force: The forces that hold the nucleus together. 

• Mass-Energy Equivalence (E = mc²): Einstein's equation and its significance in nuclear reactions.

• Nuclear Binding Energy: Understanding nuclear stability and energy release. 

• Radioactivity: Concepts of alpha, beta, and gamma decay. 

• Laws of Radioactive Decay: Half-life, mean life, and decay constant derivations. 

• Nuclear Fission and Fusion: Their role in power generation and astrophysical processes.

• Applications of Nuclear Physics: Uses of radioisotopes in medicine, industry, and archaeology.