Grade 12
  1. Solid state  1.1. Classification of solids  1.2. Crystal Lattice and Unit Cell  1.3. Packing Efficiency  1.4. Density of unit cell  1.5. Imperfections in solids (point and line defects)  1.6. Electrical Properties of Solids (Conductors, Insulators and Semiconductors)  1.7. Magnetic Properties of Solids (Diamagnetic, Paramagnetic and Ferromagnetic Materials)
  2. Solution  2.1. Types of Solutions (Homogeneous and Heterogeneous)  2.2. Expressing concentration of solutions (mass %, volume %, molarity, molality, normality, mole fraction)  2.3. Solubility of solids and gases in liquids (Henry's law)  2.4. Raoult's Law and Ideal and Non-Ideal Solutions  2.5. Syndrome properties  2.6. Abnormal molar mass and Van't Hoff factor
  3. Electrochemistry  3.1. Electrochemical cells (galvanic and electrolytic cells)  3.2. Galvanic cell and EMF of the cell  3.3. Standard electrode potential and electrochemical series  3.4. Nernst equation and its applications  3.5. Conductivity and electrolytic cells (specific, molar and equivalent conductivity)  3.6. Kohlrausch's law and its applications  3.7. Batteries (primary and secondary cells)  3.8. Corrosion and its prevention
  4. Chemical kinetics  4.1. Rate of chemical reaction  4.2. Factors affecting the reaction rate (concentration, temperature, catalyst, surface area)  4.3. Order and molecularity of the reaction  4.4. Integrated Rate Equations (Zero, First and Second Order)  4.5. Half-life of a reaction  4.6. Collision theory and activation energy  4.7. Arrhenius equation and its applications
  5. Surface chemistry  5.1. Adsorption and its types (Physicosorption and Chemisorption)  5.2. Catalysis and its types (homogeneous and heterogeneous)  5.3. Colloids and their properties (Tyndall effect, Brownian motion, coagulation)  5.4. Emulsions and gels  5.5. Applications of Colloids
  6. General principles and processes of separation of elements  6.1. Presence of metals and minerals  6.2. Concentration of ores (gravity separation, froth flotation, magnetic separation)  6.3. Extraction of raw metals (roasting, calcination, reduction)  6.4. Thermodynamic and electrochemical principles of metallurgy  6.5. Refining of metals
  7. P-block elements  7.1. Group 15 elements (nitrogen and phosphorus)  7.2. Group 16 Elements (Oxygen, Sulphur and their Compounds)  7.3. Group 17 Elements (Halogens and their Compounds)  7.4. Group 18 Elements  7.5. Properties and Trends in p-Block Elements  7.6. Important compounds of p-block elements (ammonia, phosphine, sulphuric acid, hydrochloric acid)  7.7. Interhalogen compounds and their applications
  8. d-block and f-block elements  8.1. General Properties of Transition Metals  8.2. Properties of Inner Transition Metals (Lanthanoids and Actinoids)  8.3. Lanthanoid and actinoid contractions  8.4. Coordination Chemistry of d-Block Elements
  9. Coordination compounds  9.1. Werner's theory and modern concepts  9.2. Coordination number and type of ligand  9.3. Nomenclature of Coordination Compounds  9.4. Isomerism (geometrical and optical) in coordination compounds  9.5. Bonding in Coordination Compounds (Valence Bond Theory and Crystal Field Theory)  9.6. Stability and applications of coordination compounds in medicine and industry
  10. Haloalkanes and haloarenes  10.1. Classification and nomenclature of haloalkanes and haloarenes  10.2. Physical and Chemical Properties of Haloalkanes and Haloarenes  10.3. Mechanism of Nucleophilic Substitution Reactions (SN1 and SN2)  10.4. Uses and environmental effects (ozone depletion, CFCs)
  11. Alcohol, phenol and ether  11.1. Structure and classification of alcohols, phenols and ethers  11.2. Preparation and properties of alcohols  11.3. Preparation and properties of phenol  11.4. Preparation and properties of ethers  11.5. Chemical Reactions and Uses
  12. Aldehydes, ketones and carboxylic acids  12.1. Structure and nomenclature in aldehydes, ketones and carboxylic acids  12.2. Preparation and properties of aldehydes and ketones  12.3. Chemical reactions in aldehydes, ketones and carboxylic acids (nucleophilic addition, oxidation and reduction)  12.4. Preparation and Properties of Carboxylic Acids  12.5. Chemical Reactions and Uses of Carboxylic Acids
  13. Nitrogen-containing organic compounds  13.1. Amines (classification, structure, basicity)  13.2. Preparation and properties of amines  13.3. Reactions of Amines (Diazotization, Carbylamine Reaction)  13.4. Diazonium salts and their applications in paint industry
  14.1. Carbohydrates (classification and properties)  14.2. Proteins (Structure and Function)  14.3. Enzymes (Mechanism and Function)  14.4. Nucleic acids (DNA and RNA)  14.5. Vitamins and hormones
  15. Polymer  15.1. Classification of Polymers (Addition, Condensation, Copolymers)  15.2. Types of polymerization (free radical, ionic, condensation)  15.3. Important Polymers and Their Uses  15.4. Biodegradable and non-biodegradable polymers
  16. Chemistry in Everyday Life  16.1. Drugs and their classification (analgesics, antipyretics, antibiotics, antacids)  16.2. Chemicals in food and cosmetics (preservatives, artificial sweeteners, antioxidants)  16.3. Cleaning agents and detergents (soaps, synthetic detergents, surfactants)  16.4. Environmental Chemistry (Pollution, Green Chemistry, Sustainable Chemistry)

Grade 12 → Solid state ↓


Magnetic Properties of Solids (Diamagnetic, Paramagnetic and Ferromagnetic Materials)


The magnetic properties of solids are determined by the behavior of electrons within the substances. Based on these behaviors, solids can be classified into three primary types: diamagnetic, paramagnetic, and ferromagnetic substances. This classification depends on how different substances respond to magnetic fields due to the arrangement of their atomic or molecular dipoles.

1. Introduction to magnetism

Magnetism arises from the motion of electrons and the magnetic moments they create. Electrons move in two main ways: they spin on their axis and revolve around the nucleus. Each of these motions creates a tiny magnetic field, and the combination of these microscopic fields results in the macroscopic magnetic properties of materials. We can explain these phenomena through quantum mechanical principles.

2. Diamagnetic materials

Diamagnetic materials are those that have no unpaired electrons. In these materials, all the electrons are spin paired, and therefore, the net magnetic moment is zero. When a diamagnetic material is placed in an external magnetic field, it creates an induced magnetic field in the opposite direction. This causes repulsion from the magnetic field.

The characteristics of diamagnetic materials are:

  • Weak negative sensitivity to magnetic fields.
  • To be repelled by a magnetic field.
  • Having no permanent dipole moment.

Examples of diamagnetic materials include copper, bismuth, and lead. Here is a simple graphical representation:

Diamagnetic

3. Paramagnetic materials

Paramagnetic materials have one or more unpaired electrons, which gives them a net magnetic moment. These unpaired electrons align with the external magnetic field, creating a slight attraction toward the magnetic field.

The characteristics of paramagnetic materials include:

  • Small positive sensitivity to magnetic fields.
  • Weakly attracted by magnetic fields.
  • The unpaired electrons contribute to their magnetic moment.

Examples of paramagnetic substances are aluminum, platinum, and some transition metal ions such as Fe 3+. Here is a visual illustration:

Paramagnetic

4. Ferromagnetic materials

Ferromagnetic materials have atomic magnetic moments that are aligned parallel to each other in regions called domains. Even without an external magnetic field, these domains can align due to a strong interaction between neighboring dipoles, resulting in a spontaneous magnetization.

Key features include:

  • Strong positive sensitivity to magnetic fields.
  • Being strongly attracted by magnetic fields, magnetism can persist even after the external field is removed.
  • Exhibit hysteresis, which means they have a memory of past magnetic fields.

Common examples are iron, cobalt, and nickel. An example is given below:

Ferromagnetic

In ferromagnetic materials, temperature plays an important role in determining their magnetic properties. The point at which thermal energy overcomes magnetic energy and randomizes the spin directions is called the Curie temperature.

5. Antiferromagnetism and ferrimagnetism

In addition to the classical categories of diamagnetism, paramagnetism, and ferromagnetism, there are other complex forms of magnetism, such as antiferromagnetism and ferrimagnetism.

Antiferromagnetism

In antiferromagnetic materials, the magnetic moments of adjacent ions are aligned in opposite directions, effectively cancelling each other out. This results in no net macroscopic magnetism. Antiferromagnetism is typically found in compounds of transition metals such as manganese oxide (MnO).

Ferrimagnetism

Ferrimagnetic materials have magnetic moments that oppose each other but in unequal magnitudes, resulting in a net magnetic moment. This behavior is commonly seen in certain ceramics or ferrites, such as magnetite (Fe 3 O 4).

6. Conclusion

In short, the magnetic properties of solids are determined by the arrangement and interaction of electron spins. Diamagnetic materials show weak repulsion to magnetic fields, while paramagnetic materials show weak attraction. Ferromagnetic materials show strong attraction and are able to retain magnetism due to the aligning effect of domain interactions.

Understanding these magnetic properties is essential in the development of various technologies such as memory storage devices, transformers, and motors. It is a fascinating field that combines quantum mechanics with observable macroscopic phenomena.

7. Summary table

Type Features Example
Diamagnetic
  • Weakly repelled by magnetic field
  • No unpaired electrons
  • No permanent magnetic moment
 Copper, Bismuth, Lead
Paramagnetic
  • Weakly attracted by magnetic field
  • One or more unpaired electrons
  • Net magnetic moment
 Aluminum, Platinum, Fe 3+
Ferromagnetic
  • Strongly attracted by a magnetic field
  • Permanent magnetic moment
  • Exhibits hysteresis
 Iron, cobalt, nickel

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Magnetic Properties of Solids (Diamagnetic, Paramagnetic and Ferromagnetic Materials)

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