The chapter on “Chemical Reactions and Equations” for class 10 covers various activities that illustrate key concepts in chemistry. These include demonstrating chemical changes through experiments like burning a magnesium ribbon, observing reactions between different chemical solutions, and understanding the effects of heat on certain compounds. The chapter also delves into the writing and balancing of chemical equations, types of chemical reactions (combination, decomposition, displacement, double displacement, oxidation, and reduction), and the practical implications of these reactions in everyday life, such as corrosion and rancidity.
Table of Contents
Activity – Burning of a Magnesium Ribbon in air
This activity, “Burning of a Magnesium Ribbon,” showcases a combination reaction where magnesium metal reacts with oxygen in the air to produce magnesium oxide. Key concepts include:
- Combination Reaction: Two or more substances combine to form a single product.
- Oxidation: Magnesium loses electrons to oxygen, highlighting the concept of electron transfer.
- Exothermic Reaction: The process releases energy, evident from the intense light and heat.
- Conservation of Mass: The total mass of reactants equals the mass of the product formed.
- Chemical Safety: Importance of using safety equipment due to the reaction’s intensity.
Activity – Mixing Lead Nitrate and Potassium Iodide Solutions activity
This activity, “Mixing Lead Nitrate and Potassium Iodide Solutions,” is a clear demonstration of a double displacement reaction, where:
- Ionic Compounds Exchange: Parts of two ionic compounds (lead nitrate and potassium iodide) exchange ions to form two new compounds.
- Formation of Precipitate: Lead iodide forms as a yellow precipitate, illustrating the concept of insoluble compounds separating from solution.
- Solubility and Ionic Reactions: The reaction shows how some compounds are soluble in water, like potassium nitrate, while others are not, like lead iodide.
- Conservation of Mass: The activity reinforces that mass is conserved in chemical reactions, as the total mass of reactants equals the mass of products.
This experiment provides insight into how ionic compounds interact in solutions and the concept of precipitate formation in chemical reactions.
Activity – Reacting Zinc Granules with Dilute Hydrochloric or Sulfuric Acid
This activity, “Reacting Zinc Granules with Dilute Hydrochloric or Sulfuric Acid,” demonstrates a single displacement reaction, where:
- Metal Reactivity: Zinc, a more reactive metal, displaces hydrogen from dilute hydrochloric or sulfuric acid.
- Formation of New Compounds: The reaction forms zinc chloride or zinc sulphate, along with hydrogen gas.
- Gas Evolution: The release of hydrogen gas is visible as bubbles, indicating a chemical reaction is occurring.
- Exothermic Reaction: The possible increase in temperature during the reaction suggests it is exothermic, releasing heat.
The experiment highlights the concepts of chemical reactivity, displacement reactions, and the practical application of these concepts in observing chemical changes.
Activity- Formation of Slaked Lime
The “Formation of Slaked Lime” activity illustrates a combination reaction where:
- Chemical Transformation: Calcium oxide (quicklime) reacts with water to form calcium hydroxide (slaked lime).
- Exothermic Reaction: The process releases heat, demonstrating the energy changes in chemical reactions.
- Practical Application: This reaction is fundamental in the construction industry for making materials like mortar and plaster.
The experiment emphasises the concepts of chemical reactions that form new compounds, the release of energy in exothermic processes, and the real-world application of these reactions in building and construction.
Activity Link – https://classnotes123.com/class-10-science-chapter-1-chemical-reactions-and-equations-formation-of-slaked-lime/
Activity – Heating Ferrous Sulphate Crystals
The “Heating Ferrous Sulphate Crystals” activity is centred around a decomposition reaction, where:
- Thermal Decomposition: Ferrous sulphate crystals decompose when heated, showcasing how compounds break down into simpler substances upon heating.
- Color Change Observation: The transition from green to white and then to brown indicates the stages of decomposition, providing a visual cue to the chemical changes occurring.
- Gas Evolution: The release of gases such as sulphur dioxide (SO₂) and sulphur trioxide (SO₃) signifies the breakdown of the compound into different substances.
This experiment highlights the concept of decomposition reactions driven by heat, demonstrating how compounds can change both physically and chemically under thermal energy.
Activity Link – https://classnotes123.com/class-10-science-chapter-1-chemical-reactions-and-equations-heating-ferrous-sulphate-crystals/
