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10th grade Classify reactions: synthesis, decomposition, replacement, combustion worksheet

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Classify reactions: synthesis, decomposition, replacement, combustion

Grade 10 Science Worksheet - Challenge Me

NameDate

Circle the best answer, or write your answer on the line.

  1. Ethane has 2 carbon and 6 hydrogen atoms and burns completely to CO₂ and H₂O. How many oxygen atoms end up in the products of one molecule, Bo?

  2. Butane has 4 carbon and 10 hydrogen atoms and burns completely to CO₂ and H₂O. How many oxygen atoms end up in the products of one molecule, Esme?

  3. 2 H₂ + O₂ → 2 H₂O gives off heat and light. Which two types describe it, Jun?

    • Single and double replacement
    • Decomposition and combustion
    • Synthesis and combustion

  4. Why is CH₄ + 2 O₂ → CO₂ + 2 H₂O not a synthesis reaction, Kira?

    • Its products are elements
    • It has a single reactant
    • It makes two products, not one

  5. Which equation is a decomposition, Luz?

    • 2 H₂O₂ → 2 H₂O + O₂
    • Zn + CuSO₄ → ZnSO₄ + Cu
    • 2 H₂ + O₂ → 2 H₂O

  6. Milo says Zn + CuSO₄ → ZnSO₄ + Cu is double replacement. Agree or disagree?

    • Disagree: an element replaces another
    • Agree: both of the reactants are compounds
    • Agree: zinc sulfate is a compound

  7. Noah says AgNO₃ + NaCl → AgCl + NaNO₃ is single replacement. Agree or disagree?

    • Disagree: two compounds trade partners
    • Agree: silver replaces sodium on its own
    • Agree: one product is a solid

  8. Pia says iron rusting in damp air is combustion because it uses oxygen. Agree or disagree?

    • Agree: rust is a kind of ash
    • Agree: anything that uses oxygen is burning
    • Disagree: rusting is slow, with no flame

  9. Which balanced equation shows ethane, C₂H₆, burning completely, Tala?

    • 2 C₂H₆ + 7 O₂ → 4 CO₂ + 6 H₂O
    • C₂H₆ + 3 O₂ → 2 CO₂ + 3 H₂O
    • C₂H₆ → 2 C + 3 H₂

  10. In the double replacement of CaCl₂ with Na₂CO₃, what are the products, Zee?

    • Ca₂CO₃ + NaCl
    • CaCO₃ + 2 NaCl
    • CaNa₂ + CO₃Cl₂
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10th grade Classify reactions: synthesis, decomposition, replacement, combustion worksheet – printable
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About this worksheet

Classify reactions: synthesis, decomposition, replacement, combustion. Every version has 10 questions, and the answer key prints on the second page.

What your child will learn

  • I can sort a balanced equation into synthesis, decomposition, single replacement, double replacement or combustion.
  • I can predict the products of each type from its pattern.
  • I can match what is seen (bubbles, a white solid, a coated wire) to the reaction type.
  • I can say that complete combustion of a hydrocarbon makes CO₂ and H₂O, and count the products.

Standard: HS-PS1-2

Words to know

synthesis: Two or more substances join into one product: A + B → AB

decomposition: One compound splits into simpler substances: AB → A + B

single replacement: An element takes another element's place in a compound: A + BC → AC + B

double replacement: Two compounds trade partners: AB + CD → AD + CB

combustion: A reaction with oxygen gas that gives off heat and light

Common mistakes

Your child added the product's mass to the starting mass. In a decomposition the products share the starting mass, so subtract.

Your child made one water molecule per hydrogen atom. Each H₂O holds two hydrogens, so halve the hydrogen count.

Your child counted the oxygen in CO₂ only. The water made in combustion holds oxygen too, one atom per H₂O.

Questions parents ask

What is the most common mistake with classify reactions: synthesis, decomposition, replacement, combustion?

Your child added the product's mass to the starting mass. In a decomposition the products share the starting mass, so subtract.

Are these 10th grade science worksheets free to print?

Yes. All 6 printable versions at each level are free to print, with the answer key, and no account is needed.

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