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  • Last Modified 01-07-2022

CBSE Class 12 Concepts: Important Details Here


CBSE Class 12 Concepts: Students in CBSE Class 12 need to ensure that they follow the syllabus carefully. The syllabus can therefore help them identify the CBSE Class 12 concepts each of which is important for exam preparation. The CBSE Class 12 syllabus is huge and has various subjects. 

Whether the student has chosen Arts, Science or Commerce, they must follow the concepts carefully. The CBSE Class 12 concepts can be one great way to know how to prepare for the examination. Students must also organise the concepts in a proper manner. 

CBSE Class 12 Important Concepts: Details

Students must consider organising the CBSE Class 12 important concepts so that they can prepare for their examination accordingly. It is crucial that the students chalk out a preparation strategy for every subject. In the sections below, we will be discussing the CBSE Class 12 important concepts of each subject. 

CBSE Class 12 Physics Important Concepts

CBSE Class 12 Physics consists of derivations and various topics that are extremely crucial for exam preparation. Students in the Class 12 board must ensure that they practice every topic thoroughly. 

The first unit deals with Electrostatics which is divided into two chapters that include Electric Charges and Fields and Electrostatic Potential and Capacitance. The chapter has numerous derivations related to the charge derivation and more that will help students prepare for their board examination accordingly. 

The second unit deals with Current electricity. Ohm’s Law and Kirch’s law are some of the most important concepts of Current electricity. The topics will be thoroughly explained and help students prepare for the examination. 

The third unit deals with the magnetic effects of current and magnetism. It deals with the important concept of moving charges and magnetism and matter. While dealing with the concepts such as velocity selector, cyclotron, magnetic-field, the force between two parallel current-carrying wires and more. 

The fourth unit further deals with electromagnetic induction and alternating current. It deals with different concepts such as lens law, magnetic flux, self-inductance and mutual inductance, power factor, and LC Oscillations. 

The fifth unit deals with electromagnetic waves. The important details concepts covered in this chapter include EM Waves, Nature of EM waves, Displacement current and more. 

The sixth unit is of utmost importance where optics are discussed. It is divided into two chapters- Ray Optics and Optical Instrument and Wave Optics. Ray Optics and Optical Instrument deal with important chapters that include:

Image formation by spherical mirrors and lenses

Total internal reflection

Natural phenomenon due to light

Wave Optics is a final chapter that deals with important concepts like incoherent and coherent waves addition, diffraction of light, polarisation by scattering, and resolving power of optical instruments. 

The seventh unit is known as Radiation and Matter Have A Dual Nature. Some of the most important concepts are covered in this chapter. It deals with essential concepts like the de Broglie hypothesis, the photoelectric effect, Einstein’s photoelectric equation and the de Broglie hypothesis. 

CBSE Class 12 Chemistry Important Concepts

CBSE Chemistry Class 12 has a vast syllabus. Students must make it a point to follow and discuss the concepts thoroughly to score higher marks in the examination. Students must refer to the sections given below to understand the important concepts that they must prepare for their board exams:

Unit: Solubility of gases in liquids

  • How it changes with changes in temperature etc.
  • Colligative properties
  • Raoult’s law 
  • Relative lowering of vapour pressure 
  • Depression of freezing point 
  • Elevation of boiling point Osmotic pressure
  • Determination of molecular masses using colligative properties Abnormal molecular mass
  • Van’t Hoff factor

Unit 3: Electrochemistry –

  • Redox reactions (prepare definition with examples, corrosion is an example of redox reaction)
  • Conductance in electrolytic solutions 
  • Specific and molar conductivity 
  • Variations of conductivity with concentration (Theoretical question can be asked)
  • Kohlrausch’s Law (Numerical problems are expected)
  • Electrolysis and law of electrolysis (Faradays’ laws are also important)
  • Dry cell-electrolytic cells and Galvanic cells (Theoretical question can be asked)
  • Lead accumulator (Theoretical question can be asked)
  • EMF of a cell (Numerical problems are expected)
  • Standard electrode potential (Very important)
  • Nernst equation and its application to chemical cells
  • Relation between Gibbs energy change and emf of a cell
  • Fuel cells
  • Corrosion 

Unit 4: Chemical Kinetics –

  • Rate of a reaction (Average and instantaneous)
  • Factors affecting rate of reaction: concentration, temperature, catalyst
  • Conceptual questions are expected
  • Order and molecularity of a reaction (Very important)
  • Rate law and specific rate constant  (Very important)
  • Integrated rate equations and half-life (only for zero and first-order reactions)
  • Concept of collision theory (elementary idea, no mathematical treatment)
  • Activation energy 
  • Arrhenius equation

Unit 5: Surface Chemistry –

  • Adsorption – physisorption and chemisorption 
  • Factors affecting adsorption of gases on solids
  • Conceptual questions are expected
  • Catalysis
  • Homogenous and heterogeneous activity and selectivity
  • Enzyme catalysis colloidal state distinction between true solutions
  • Colloids and suspension
  • Lyophilic, lyophobic multi-molecular and macromolecular colloids 
  • Properties of colloids
  • Tyndall effect 
  • Brownian movement 
  • Electrophoresis
  • Coagulation
  • Emulsion – types of emulsions
  • Unit 6: General Principles and Processes of Isolation of Elements 
  • Principles and methods of extraction – concentration, oxidation, reduction (Very important)
  • Electrolytic method and refining
  • Occurrence and principles of extraction of aluminium, copper, zinc & iron

Unit 7: p Block Elements –

  • Group 15 Elements:
  • Electronic configuration, occurrence, oxidation states, trends in physical and chemical properties
  • Conceptual questions are expected
  • Nitrogen, preparation properties & uses
  • Conceptual questions are expected
  • Compounds of Nitrogen
  • Preparation and properties of Ammonia and Nitric acid,
  • Oxides of Nitrogen (Structure only) 
  • Phosphorus 
  • Allotropic forms
  • Compounds of Phosphorus
  • Preparation and properties of Phosphine, Halides and Oxoacids (elementary idea only)

Group 16 Elements:

  • Electronic configuration, oxidation states, occurrence, trends in physical and chemical properties
  • Conceptual questions are expected
  • Dioxygen: Preparation, Properties& Uses 

Classification of oxides

  • Ozone 
  • Sulphur -allotropic forms
  • Compounds of sulphur: Preparation properties and uses of sulphur-dioxide
  • Sulphuric acid: industrial process of manufacture, properties and uses (Very important)
  • Oxoacids of Sulphur (Structures only)

Group 17 Elements:

  • Electronic configuration, oxidation states, occurrence, trends in physical and chemical properties
  • Compounds of halogens
  • Preparation properties and uses of chlorine and hydrochloric acid (Very important)
  • Interhalogen compounds
  • Oxoacids of halogens
  • Group 18 Elements:
  • Electronic configuration, occurrence, trends in physical and chemical properties & uses

Unit 8: d and f Block Elements –

  • Electronic configuration, occurrence and characteristics of transition metals
  • General trends in properties of the first-row transition metals –
  • metallic character
  • ionization enthalpy (very important)
  • oxidation states (very important)
  • ionic radii
  • colour
  • catalytic property
  • magnetic properties
  • interstitial compounds (very important)
  • alloy formation
  • Preparation and properties of K2Cr2O7 and KMnO4

Lanthanoids –

  • Electronic configuration
  • Oxidation states
  • Chemical reactivity and lanthanoid contraction and its consequences
  • Actinoids –
  • Electronic configuration, oxidation states and comparison with lanthanoids

Unit 9: Coordination Compounds –

  • Ligands
  • Coordination number, colour, magnetic properties and shapes 
  • IUPAC nomenclature of mononuclear coordination compounds
  • Bonding,
  • Werner’s theory  
  • VBT 
  •  CFT 
  • Structure and stereoisomerism 

Unit 10: Haloalkanes and Haloarenes 


  • Nomenclature
  • Nature of C-X bond
  • Physical and chemical properties
  • Mechanism of substitution reactions
  • Optical rotation


  • Nature of C -X bond,
  • Substitution reactions (Directive influence of halogen in monosubstituted compounds only.
  • Uses and environmental effects of –
  • Dichloromethane
  • Trichloromethane
  • Tetrachloromethane
  • Iodoform
  • Freons
  • DDT

Unit 11: Alcohols, Phenols and Ethers 


  • Nomenclature
  • Methods of preparation
  • Physical and chemical properties (primary alcohols only)
  • Identification of primary, secondary and tertiary alcohols (very important)
  • Mechanism of dehydration used with special reference to methanol and ethanol


  • Nomenclature
  • Methods of preparation
  • Physical and chemical properties
  • Acidic nature of phenol
  • Electrophilic substitution reactions
  • Uses of phenols


  • Nomenclature
  • Methods of preparation
  • Physical and chemical properties
  • Uses

Frequently Asked Questions on CBSE Class 12 Important Concepts

Some of the frequently asked questions about the CBSE Class 12 important concepts include the following:

Q.1: Is CBSE Class 12 important?
Ans: Yes. Students looking forward to scoring good marks in the exam and establishing a good career should consider preparing for CBSE Class 12 thoroughly. 

Q.2: Are derivations important for students in Class 12?
Ans: Yes. Students should consider practicing the derivations from Physics and Chemistry to score good marks in the exam. 

Q.3: Is CBSE Class 12 difficult?
No. Students who prepare for the exam thoroughly can score nice marks in the exam. To ensure they don’t face any difficulties, the students must practice the previous year’s question papers and sample papers thoroughly. 

Q.4: Is 80% a good percentage in CBSE Class 12?
Ans: Yes. It is a really good score. Students should however practice the sample papers thoroughly so that they score 80% and above. 

Q.5: Which chapter is the most important in CBSE Class 12 Physics?
Ans: Almost all the chapters are important in CBSE Class 12 Physics. Students must refer all the units and prepare for their exams accordingly. 

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