Class 10 • Chemistry • Chapter 1
Chemical Reactions and Equations
True & False Quiz
React. Balance. Transform.
✓True
✗False
25
Questions
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Ch.1
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Why True & False for Chemical Reactions and Equations?
How this format sharpens your conceptual clarity
🔵 Chemical reactions are the language of matter transforming — from rusting iron to digesting food, every change is governed by these laws.
✅ T/F questions target balancing equations, types of reactions (combination, decomposition, displacement, redox), and the law of conservation of mass.
🎯 Classic trap: a physical change (melting ice) is NOT a chemical reaction — no new substance is formed.
📋
Read each statement carefully. Click True or False — instant feedback with explanation appears. Submit anytime; unattempted questions are marked Skipped.
Q 1
Every chemical reaction must involve a change in energy.
Q 2
Rusting of iron is a physical change.
Q 3
Magnesium reacts with oxygen to form magnesium oxide.
Q 4
In a balanced chemical equation, the mass of reactants and products is equal.
Q 5
Chemical equations must show physical states of reactants and products.
Q 6
Precipitation is a type of chemical reaction.
Q 7
All combination reactions are exothermic.
Q 8
Decomposition reactions always require heat.
Q 9
The reaction of silver chloride with sunlight is an example of a photochemical reaction.
Q 10
Respiration in living organisms is a chemical reaction.
Q 11
Oxidation always means addition of oxygen to a substance.
Q 12
In displacement reactions, a more reactive element replaces a less reactive element from its compound.
Q 13
Photosynthesis is an example of an endothermic reaction.
Q 14
All decomposition reactions are the exact opposite of combination reactions.
Q 15
Chemical equations can be balanced by adjusting the coefficients only.
Q 16
Carbon dioxide is liberated when dilute hydrochloric acid reacts with sodium carbonate.
Q 17
The formation of curd from milk is a chemical change.
Q 18
Rust is produced when iron reacts with dry oxygen only.
Q 19
Precipitate does not form in a neutralization reaction.
Q 20
A chemical reaction cannot occur without a change in color, temperature, or state.
Q 21
Photosynthesis produces heat as a product.
Q 22
The reaction between lead nitrate and potassium iodide forms a yellow precipitate.
Q 23
Double displacement reactions always result in gas formation.
Q 24
Combination reactions always require heat to occur.
Q 25
Burning of magnesium ribbon produces a bright white light due to formation of magnesium oxide.
Key Takeaways — Chemical Reactions and Equations
Core facts for CBSE Boards & exams
1
Law of Conservation of Mass: total mass of reactants = total mass of products.
2
Combination: A + B → AB; Decomposition: AB → A + B (opposite of combination).
3
Displacement: A + BC → AC + B (more reactive A displaces B).
4
Double Displacement: AB + CD → AD + CB (exchange of ions).
5
Oxidation = loss of electrons / gain of oxygen; Reduction = gain of electrons / loss of oxygen.
6
Redox reactions involve simultaneous oxidation and reduction — they always occur together.