Class 10 Science Chemical Reactions and Equations Most Important Questions
Most Important Questions for Class 10 Science Chemical Reactions and Equations. Try first, then reveal the answer. These are exam-oriented practice items, not copied board papers.
Practice questions aligned to NCERT topics used in CBSE classrooms. These are original exam-oriented questions for revision — not official CBSE board papers and not a guarantee of any exam question. Always match the textbook issued by your school and the latest PDFs on ncert.nic.in and cbseacademic.nic.in.
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Practice set
Q1MCQ1 markEasyRevision pick
Choose the correct statement related to Balanced equation in the chapter Chemical Reactions and Equations.
A. An exothermic reaction releases heat to the surroundings
B. A decomposition reaction splits one compound into two or more products, often with heat, light or electricity
C. Mass need not be conserved
D. A balanced chemical equation has the same number of atoms of each element on both sides
Answer
D. A balanced chemical equation has the same number of atoms of each element on both sides
Explanation
A balanced chemical equation has the same number of atoms of each element on both sides. The other options mix ideas from nearby topics or reverse the textbook fact.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q5MCQ1 markModerateRevision pick
Choose the correct statement related to Redox in the chapter Chemical Reactions and Equations.
A. Combination, decomposition, displacement, double displacement
B. Precipitation reactions
C. Oxidation and reduction occur together in a redox reaction
D. An endothermic reaction absorbs heat from the surroundings
Answer
C. Oxidation and reduction occur together in a redox reaction
Explanation
Oxidation and reduction occur together in a redox reaction. The other options mix ideas from nearby topics or reverse the textbook fact.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q9MCQ1 markEasyRevision pick
Choose the correct statement related to Chemical Reactions and Equations in the chapter Chemical Reactions and Equations.
A. A chemical equation must be balanced for mass
B. A balanced chemical equation has the same number of atoms of each element on both sides
C. Redox: oxidation is gain of oxygen or loss of electrons as taught
D. This idea is not part of the NCERT chapter
Answer
A. A chemical equation must be balanced for mass
Explanation
A chemical equation must be balanced for mass. The other options mix ideas from nearby topics or reverse the textbook fact.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q13MCQ1 markEasyRevision pick
Choose the correct statement related to Chemical Reactions and Equations in the chapter Chemical Reactions and Equations.
A. In a combination reaction two or more substances join to form a single product
B. The textbook says the opposite of this statement
C. Oxidation and reduction occur together in a redox reaction
D. Precipitation reactions
Answer
D. Precipitation reactions
Explanation
Precipitation reactions. The other options mix ideas from nearby topics or reverse the textbook fact.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q17MCQ1 markEasyRevision pick
Choose the correct statement related to Displacement in the chapter Chemical Reactions and Equations.
A. A decomposition reaction splits one compound into two or more products, often with heat, light or electricity
B. A more reactive metal can displace a less reactive metal from its salt solution
C. Combination, decomposition, displacement, double displacement
D. An endothermic reaction absorbs heat from the surroundings
Answer
B. A more reactive metal can displace a less reactive metal from its salt solution
Explanation
A more reactive metal can displace a less reactive metal from its salt solution. The other options mix ideas from nearby topics or reverse the textbook fact.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q413 Mark3 marksModerateRevision pick
Explain Combination reaction in about three points, with one example.
Answer
In a combination reaction two or more substances join to form a single product. Example: CaO + H2O → Ca(OH)2
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q453 Mark3 marksModerateRevision pick
Explain Exothermic in about three points, with one example.
Answer
An exothermic reaction releases heat to the surroundings. Example: Respiration and many combustions
Explanation
Three-mark questions want a short explanation, not a full essay. Link the idea to a figure or an activity.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q575 Mark5 marksDifficultRevision pick
Write a long answer on Redox. Include definition, explanation and one application.
Answer
Redox — Oxidation and reduction occur together in a redox reaction. Explain the idea in order (definition → working → result). End with one application from daily life or a numerical/diagram if the chapter has one.
Explanation
Long answers are marked for structure. Use headings or numbered steps so the examiner can see each part.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q69Case Based4 marksModerateRevision pick
A student is revising Chemical Reactions and Equations and notes: “A more reactive metal can displace a less reactive metal from its salt solution.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Displacement.
(ii) A more reactive metal can displace a less reactive metal from its salt solution.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
Case-based items recycle a short story. Pull the fact out first, then apply it. This is original practice in CBSE case style — not a copied board paper.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q73Case Based4 marksModerateRevision pick
A student is revising Chemical Reactions and Equations and notes: “A precipitate is an insoluble solid formed in a double-displacement reaction.” Using this case, answer: (i) Name the idea. (ii) State it in your own words. (iii) Give one classroom or daily-life use.
Answer
(i) Precipitation.
(ii) A precipitate is an insoluble solid formed in a double-displacement reaction.
(iii) Apply it in a school experiment, a labelled diagram, or a situation described in the NCERT chapter.
Explanation
Case-based items recycle a short story. Pull the fact out first, then apply it. This is original practice in CBSE case style — not a copied board paper.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q77Competency Based3 marksModerateRevision pick
Competency practice: A classmate can recall the heading Chemical Reactions and Equations but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — Exothermic vs endothermic. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q81Competency Based3 marksDifficultRevision pick
Competency practice: A classmate can recall the heading Decomposition but cannot explain it. How will you teach it in two steps using the textbook idea?
Answer
Step 1: State the fact — A decomposition reaction splits one compound into two or more products, often with heat, light or electricity. Step 2: Show one example or diagram from the chapter and ask the classmate to repeat it in their own words.
Explanation
Competency-based items check whether you can use a concept, not only name it. Teach-back is a simple way to prove understanding.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
Q93HOTS3 marksDifficultRevision pick
HOTS: If someone ignored the idea “In a combination reaction two or more substances join to form a single product”, what mistake could they make while solving a question from Chemical Reactions and Equations?
Answer
They would use the wrong term or the reverse relation. Remember: In a combination reaction two or more substances join to form a single product. Always check the NCERT definition before jumping to a formula or a long explanation.
Explanation
HOTS items ask you to predict an error. That is still chapter revision — not a claim that this exact wording will appear in the board exam.
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Class: Class 10 · Subject: Science · Chapter: Chemical Reactions and Equations · Original GKSchools practice (NCERT-aligned, not an official CBSE paper).
FAQs
Are these official CBSE board questions?
No. They are original practice questions aligned to NCERT topics used in CBSE classrooms. Official sample papers are published on cbseacademic.nic.in.
Will these questions appear in the board exam?
Nobody can promise a question. Use them for revision of frequently tested concepts and exam-style practice.
Is the chapter list the latest NCERT list?
Yes, the catalog follows current NCERT textbooks used in CBSE schools (including new middle-stage books such as Ganita Prakash and Curiosity). Always match the book issued by your school.
How should I use the 100 questions?
Try the question first, then tap Show answer. Mix MCQs with long answers. Revise formulas and diagrams from the textbook alongside this set.
Where are NCERT solutions?
Open the NCERT-style practice link on this subject or chapter. For word-for-word textbook exercise answers, use the NCERT book itself; we do not copy solution keys from other websites.
What is the suggested URL pattern?
Hub /cbse/, then /cbse/class-10/, then subject and chapter slugs.
Why is this a separate URL?
So students searching for “Most Important Questions” land on a filtered set, while the chapter page remains the full 100-question bank. Same facts, different search intent.
Today's 3-step path
Follow this loop every day: mixed test, current affairs, then today's subject. A new set arrives tomorrow.
