Chemical Reactions and Equations — Class 10 Science MCQs

NCERT | CBSE Curriculum

Practice 100+ MCQs on Chemical Reactions and Equations for Class 10.
Balancing equations, combination, decomposition, displacement & redox reactions — with answers.
Instant answers & performance report.

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Quick Revision: Chemical Reactions and Equations

  • Chemical Reaction: Process where reactants transform into products with new properties.
  • Indicators of Reaction: Change in state, colour, temperature, or evolution of gas.
  • Chemical Equation: Symbolic representation using formulas and symbols.
  • Balanced Equation: Equal number of each atom on both sides (Law of Conservation of Mass).
  • Combination Reaction: Two or more substances → Single product (A + B → AB).
  • Decomposition Reaction: Single compound → Two or more simpler substances (AB → A + B).
  • Displacement Reaction: More reactive element replaces less reactive one from compound (A + BC → AC + B).
  • Double Displacement: Exchange of ions between two compounds (AB + CD → AD + CB).
  • Redox Reaction: Both oxidation and reduction occur simultaneously.
  • Oxidation: Gain of oxygen or loss of hydrogen.
  • Reduction: Loss of oxygen or gain of hydrogen.
  • Oxidising Agent: Substance that gets reduced (causes oxidation).
  • Reducing Agent: Substance that gets oxidised (causes reduction).
  • Exothermic Reaction: Releases heat (e.g., respiration, combustion).
  • Endothermic Reaction: Absorbs heat (e.g., decomposition of calcium carbonate).
  • Corrosion: Gradual destruction of metals by chemical reaction (rusting of iron).
  • Rancidity: Oxidation of fats/oils in food causing bad smell/taste.
  • Prevention of Rancidity: Antioxidants, refrigeration, airtight containers, nitrogen flushing.
  • Activity Series: Metals arranged by decreasing reactivity (determines displacement).

External Resources: Byjus - Chemical Reactions | Khan Academy - Chemical Reactions

Chapter Summary: Chemical Reactions and Equations

Chemical Reactions and Equations MCQ Class 10 introduces you to the fundamental language of chemistry—how substances interact and transform. We start by understanding the key indicators of chemical reactions, then learn to write and balance chemical equations accurately using the Law of Conservation of Mass.

We classify reactions into combination, decomposition, displacement, and double displacement types. The chapter also covers redox reactions, explaining oxidation and reduction in terms of oxygen/hydrogen transfer. Practical applications like corrosion (rusting) and rancidity of food make the concepts relevant to daily life.

This chapter forms the foundation for predicting reaction outcomes and understanding chemical processes in industries, biology, and environmental science. Regular practice builds speed in equation balancing, improves ability to predict products, and reinforces theoretical concepts through application.