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 → Chemical kinetics ↓


Rate of chemical reaction


In chemical kinetics, the rate of a chemical reaction refers to how quickly a reactant is consumed or how quickly a product is formed. Understanding the rate of a chemical reaction is important because it tells us about the speed of the reaction and can help us control the reaction conditions for optimal results.

What is the reaction rate?

The reaction rate is often represented as the change in concentration of the reactant or product over time. Chemical reactions occur because molecules collide and interact with each other. The reaction rate can be affected by many factors, such as temperature, concentration of reactants, surface area, and the presence of catalysts.

Understanding reaction rate using a simple example

Let's consider a simple chemical reaction where hydrogen and oxygen react to form water:

2H 2 + O 2 → 2H 2 O

You can measure the rate of this reaction by seeing how quickly the concentration of hydrogen (H2) decreases or how quickly the concentration of water (H2O) increases.

Factors affecting the reaction rate

1. Concentration of reactants

The concentration of reactants plays an important role in determining the reaction rate. Generally, an increase in the concentration of reactants leads to an increase in the reaction rate. The reason behind this is that higher concentration of reactants leads to more collisions per unit time.

Example: If you double the concentration of reactant A in a reaction, the number of collisions between A and the other reactants increases, speeding up the reaction.

2. Temperature

Temperature is another important factor that affects the rate of a chemical reaction. When temperature increases, molecules move faster due to greater kinetic energy, leading to more frequent and more energetic collisions.

Example: Consider the reaction in which an enzyme acts as a catalyst to decompose hydrogen peroxide (H2O2) into water and oxygen. At higher temperatures, the decomposition rate increases considerably.

3. Surface area

The surface area of the reactants can affect reaction rates, especially for solids. Increasing the surface area leaves more particles exposed and available for collisions.

Example: Converting a solid reactant into a powder increases its surface area, which speeds up the reaction rate because more particles are exposed to collision.

4. Catalyst

Catalysts are substances that increase the reaction rate without being consumed in the reaction. They work by providing an alternative reaction pathway with a lower activation energy.

Example: In the decomposition of hydrogen peroxide, the addition of a small amount of manganese dioxide (MnO2) dramatically increases the rate of evolution of oxygen gas.
Reactants Products

Mathematical expression of reaction rate

The rate of a reaction can be expressed mathematically by the following formula:

rate = - (Δ[Reactant]/Δt) = Δ[Product]/Δt

This equation shows that the rate can be determined by measuring the rate of decrease in the concentration of a reactant (- Δ[reactant]/Δt) or the rate of increase in the concentration of a product (Δ[product]/Δt) over a period of time (Δt).

Example of calculating the reaction rate

Suppose your response is this:

A + B → C

If the concentration of A decreases by 0.03 M in 10 seconds, the rate of the reaction may be calculated as:

rate = - Δ[A]/Δt = - (-0.03 M) / 10 s = 0.003 M/s

Reaction rate order

The reaction rate order describes how the rate is affected by the concentration of the reactants. Rates can have different orders with respect to each reactant, and the overall order is the sum of the individual orders.

Example of a reaction sequence

Consider the response:

2NO + O 2 → 2NO 2

If the rate law is given as:

Rate = k[NO] 2 [O 2]

This reaction is second order with respect to NO and first order with respect to O 2, making it a third order reaction overall.

Conclusion

Understanding the rate of a chemical reaction and the factors that affect it is important for controlling and optimizing chemical processes. By applying the principles of chemical kinetics, we can predict how changes in conditions will affect the reaction rate, allowing for the rational design of experiments and chemical reactors.


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Rate of chemical reaction

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