Chemical Reactions and Equations

Grade 10 Science — Chemical Reactions and Equations: 25 practice questions with instant scoring and explanations.

1. Which of the following is an example of a combination reaction?
2. In the reaction 2Fe + 3Cl₂ → 2FeCl₃, what is the coefficient of Cl₂?
3. Which type of reaction involves the exchange of ions between two compounds?
4. What is the oxidation state of carbon in CO₂?
5. A reaction in which a compound breaks down into simpler substances is called:
6. Which reaction is endothermic?
7. Balance the equation: Fe + O₂ → Fe₂O₃. What are the coefficients?
8. Rusting of iron is an example of:
9. In a redox reaction, which element loses electrons?
10. Which of these is a displacement reaction?
11. What does the symbol '→' indicate in a chemical equation?
12. Rancidity is the process of:
13. Which reaction releases heat energy?
14. In the reaction Mg + 2HCl → MgCl₂ + H₂, which element is oxidised?
15. Which of the following is NOT a type of chemical reaction?
16. Complete and balance: 2Na + 2H₂O → 2NaOH + ?
17. The process of iron combining with oxygen to form rust is:
18. Which statement about exothermic reactions is true?
19. In the reaction: CaCO₃ → CaO + CO₂, what type of reaction is this?
20. Which of the following pairs will undergo a displacement reaction?
21. The substance that prevents or delays corrosion is called:
22. In the equation 2H₂O₂ → 2H₂O + O₂, the oxygen in H₂O has an oxidation state of:
23. Which of these reactions is both a decomposition and an endothermic reaction?
24. What happens to the mass of a substance during a chemical reaction?
25. In the reaction Cl₂ + 2KBr → 2KCl + Br₂, which element is the oxidising agent?