⚗️ Part 1: Indicators of Chemical Change

1. Which of the following are indicators that a chemical reaction has occurred? (Check all that apply)

Colour change

Formation of a gas (bubbling)

Formation of a precipitate

Temperature change

Change in shape only

2. When magnesium ribbon burns in air, it produces a bright white light and white ash. This is an example of:

A physical change

A chemical change

No change at all

Only a temperature change

3. Describe what you would observe when zinc metal is added to hydrochloric acid:

⚖️ Part 2: Balancing Chemical Equations

4. Balance the following chemical equations by filling in the coefficients:

a) _____ H₂ + _____ O₂ → _____ H₂O

b) _____ Mg + _____ HCl → _____ MgCl₂ + _____ H₂

c) _____ Fe + _____ O₂ → _____ Fe₂O₃

5. Show your working for balancing this equation:

_____ Al + _____ CuSO₄ → _____ Al₂(SO₄)₃ + _____ Cu

6. The law of conservation of mass states that:

Mass can be created during a chemical reaction

Mass can be destroyed during a chemical reaction

Mass is neither created nor destroyed in a chemical reaction

Mass always increases in a chemical reaction

🔥 Part 3: Energy Changes in Reactions

7. Match the reaction type with its energy characteristic:

1. Exothermic reaction

2. Endothermic reaction

3. Combustion reaction

A. Absorbs energy from surroundings

B. Always exothermic, produces heat and light

C. Releases energy to surroundings

8. When ammonium chloride dissolves in water, the temperature of the solution decreases. This is an example of:

An exothermic process

An endothermic process

No energy change

A combustion reaction

9. Explain why a hand warmer packet becomes hot when activated:

🧪 Part 4: Types of Chemical Reactions

10. Fill in the blanks to complete the general equations for different reaction types:

a) Synthesis: A + B → __________

b) Decomposition: AB → __________ + __________

c) Single displacement: A + BC → __________ + __________

d) Double displacement: AB + CD → __________ + __________

11. Classify each reaction by writing the type in the space provided:

a) 2H₂O₂ → 2H₂O + O₂ ________________

b) Zn + CuSO₄ → ZnSO₄ + Cu ________________

c) N₂ + 3H₂ → 2NH₃ ________________

d) AgNO₃ + NaCl → AgCl + NaNO₃ ________________

12. Which type of reaction is represented by photosynthesis?

Decomposition

Synthesis

Single displacement

Combustion

🔬 Part 5: Concept Mapping and Analysis

13. Create a concept map connecting the following terms. Draw lines and label the connections:

Terms: Chemical Reaction, Conservation of Mass, Reactants, Products, Balanced Equation, Energy Change

14. Explain how balancing chemical equations demonstrates the law of conservation of mass:

15. A student claims that when wood burns, mass is lost because the wood disappears. Explain why this thinking is incorrect and what actually happens to the mass:

Chemical Reactions Review

Chemical Reactions Review

⚗️ Part 1: Indicators of Chemical Change

⚖️ Part 2: Balancing Chemical Equations

🔥 Part 3: Energy Changes in Reactions

🧪 Part 4: Types of Chemical Reactions

🔬 Part 5: Concept Mapping and Analysis

About This Worksheet

Free in Kuraplan

Print-Ready

AI-Generated

For Teachers & Parents

Need a custom version of this worksheet?

More Science Worksheets

Science Skills Review Worksheet

Year 3 Science Comprehension

Year 6 Science Exploration

Homeschool Science Worksheet

Earth Science Exploration Worksheet

Earth Science Question Worksheet

Soil Science Through Drama

Elemental Science Exploration

Explore more free resources