NECO chemistry Past Questions and Answers
Preparing for NECO Chemistry can feel challenging, but the right practice makes it much easier. One of the best ways to get ready is by using past questions, which help you understand how topics are tested and what to expect in the exam.
NECO Chemistry past questions and answers give you a chance to test yourself, learn from mistakes, and improve your confidence. With regular practice, you can build speed and accuracy, which will make it easier for you to perform well on exam day.
NECO Chemistry Past Questions and Answers
1. Which of the following is a physical change? A. Burning of paper B. Rusting of iron C. Dissolving salt in water D. Cooking food. Answer: C
2. The smallest particle of an element that can take part in a chemical reaction is called A. Molecule B. Atom C. Ion D. Compound. Answer: B
3. Which of the following elements is a metal? A. Oxygen B. Nitrogen C. Sodium D. Chlorine. Answer: C
4. The pH value of a neutral solution is A. 0 B. 7 C. 14 D. 10. Answer: B
5. Which gas is responsible for rusting? A. Hydrogen B. Oxygen C. Nitrogen D. Carbon dioxide. Answer: B
6. An acid turns blue litmus paper to A. Green B. Red C. Yellow D. Black. Answer: B
7. Which of the following is an example of a compound? A. Iron B. Air C. Water D. Gold. Answer: C
8. The process of converting a liquid to gas is called A. Condensation B. Freezing C. Evaporation D. Sublimation. Answer: C
9. Which of the following is a noble gas? A. Oxygen B. Helium C. Nitrogen D. Hydrogen. Answer: B
10. The atomic number of an element is equal to the number of A. Neutrons B. Protons C. Electrons and neutrons D. Ions. Answer: B
11. Which of the following is a base? A. HCl B. NaOH C. H2SO4 D. HNO3. Answer: B
12. The gas used in filling balloons is A. Oxygen B. Nitrogen C. Helium D. Carbon dioxide. Answer: C
13. Which of the following is an indicator? A. Water B. Litmus C. Salt D. Sugar. Answer: B
14. The boiling point of water is A. 0°C B. 50°C C. 100°C D. 200°C. Answer: C
15. Which of the following is an example of a mixture? A. Water B. Salt C. Air D. Carbon dioxide. Answer: C
16. The chemical symbol for sodium is A. So B. Na C. Sn D. Sd. Answer: B
17. Which of the following is a non-metal? A. Copper B. Iron C. Sulphur D. Zinc. Answer: C
18. The process of rusting requires water and A. Hydrogen B. Oxygen C. Nitrogen D. Carbon monoxide. Answer: B
19. Which of the following is used to test for starch? A. Iodine B. Litmus C. Methyl orange D. Phenolphthalein. Answer: A
20. The SI unit of mass is A. Gram B. Kilogram C. Pound D. Ton. Answer: B
NECO Chemistry Past Questions and Answers
21. Which of the following is an alkali? A. HCl B. NaOH C. CO2 D. H2SO4. Answer: B
22. The valency of oxygen is A. 1 B. 2 C. 3 D. 4. Answer: B
23. Which of the following is a greenhouse gas? A. Oxygen B. Nitrogen C. Carbon dioxide D. Hydrogen. Answer: C
24. Which process separates insoluble solids from liquids? A. Filtration B. Distillation C. Evaporation D. Chromatography. Answer: A
25. The colour of methyl orange in acid is A. Yellow B. Red C. Blue D. Green. Answer: B
26. Which of the following is an element? A. Water B. Salt C. Oxygen D. Sugar. Answer: C
27. The gas that supports combustion is A. Nitrogen B. Oxygen C. Carbon dioxide D. Hydrogen. Answer: B
28. Which of the following is used in making fertilizers? A. Nitrogen B. Helium C. Neon D. Argon. Answer: A
29. The process of turning solid directly into gas is called A. Sublimation B. Melting C. Freezing D. Condensation. Answer: A
30. Which of the following is acidic? A. NaOH B. KOH C. HCl D. Ca(OH)2. Answer: C
31. The main component of natural gas is A. Methane B. Ethane C. Propane D. Butane. Answer: A
32. Which of the following is used to soften hard water? A. Salt B. Soap C. Washing soda D. Sugar. Answer: C
33. The chemical formula of water is A. H2O B. CO2 C. NaCl D. H2SO4. Answer: A
34. Which of the following is a salt? A. HCl B. NaOH C. NaCl D. H2SO4. Answer: C
35. The number of electrons in a neutral atom equals the number of A. Protons B. Neutrons C. Ions D. Compounds. Answer: A
36. Which of the following is a gas? A. Iron B. Water C. Oxygen D. Salt. Answer: C
37. The process of cooling gas to liquid is called A. Evaporation B. Condensation C. Sublimation D. Freezing. Answer: B
38. Which of the following is used as fuel? A. Oxygen B. Hydrogen C. Nitrogen D. Neon. Answer: B
39. The colour of phenolphthalein in base is A. Colourless B. Pink C. Yellow D. Red. Answer: B
40. Which of the following is an acid? A. NaOH B. KOH C. HCl D. CaO. Answer: C
NECO Chemistry Past Questions and Answers
41. The particle responsible for chemical bonding is A. Neutron B. Proton C. Electron D. Nucleus. Answer: C
42. Which of the following is insoluble in water? A. Sugar B. Salt C. Sand D. Alcohol. Answer: C
43. The unit of temperature is A. Meter B. Kelvin C. Second D. Ampere. Answer: B
44. Which of the following is a liquid? A. Oxygen B. Water C. Nitrogen D. Carbon dioxide. Answer: B
45. The process of heating a substance to dryness is called A. Evaporation B. Boiling C. Distillation D. Filtration. Answer: A
46. Which of the following is used to measure volume? A. Thermometer B. Balance C. Measuring cylinder D. Meter rule. Answer: C
47. The element with atomic number 1 is A. Helium B. Hydrogen C. Oxygen D. Nitrogen. Answer: B
48. Which of the following is a chemical change? A. Melting ice B. Breaking glass C. Burning wood D. Dissolving salt. Answer: C
49. The gas produced during respiration is A. Oxygen B. Nitrogen C. Carbon dioxide D. Hydrogen. Answer: C
50. Which of the following is a metal oxide? A. CO2 B. SO2 C. Na2O D. NO2. Answer: C
51. The process of separating liquids with different boiling points is A. Filtration B. Distillation C. Evaporation D. Decantation. Answer: B
52. Which of the following is used in electrolysis? A. Heat B. Electricity C. Light D. Pressure. Answer: B
53. The substance that dissolves solute is called A. Solvent B. Solution C. Mixture D. Compound. Answer: A
54. Which of the following is a homogeneous mixture? A. Sand and water B. Oil and water C. Salt solution D. Soil. Answer: C
55. The chemical symbol for iron is A. Ir B. Fe C. In D. Io. Answer: B
56. Which of the following is used in making glass? A. Sand B. Salt C. Sugar D. Wood. Answer: A
57. The number of neutrons is equal to A. Atomic number B. Mass number minus atomic number C. Number of electrons D. Number of ions. Answer: B
58. Which of the following is a reducing agent? A. Oxygen B. Hydrogen C. Nitrogen D. Carbon dioxide. Answer: B
59. The process of gaining oxygen is called A. Reduction B. Oxidation C. Neutralization D. Evaporation. Answer: B
60. Which of the following is used to detect water? A. Blue litmus B. Anhydrous copper(II) sulphate C. Methyl orange D. Phenolphthalein. Answer: B
NECO Chemistry Past Questions and Answers on Theory
61. Define an atom and state its components.
An atom is the smallest particle of an element that retains its chemical properties. It consists of protons, neutrons, and electrons.
62. What is a molecule? Give one example.
A molecule is the smallest unit of a substance that can exist independently. An example is water (H2O).
63. Define an acid and give one example.
An acid is a substance that produces hydrogen ions in solution. An example is hydrochloric acid.
64. What is a base? Give one example.
A base is a substance that reacts with acids to form salt and water. An example is sodium hydroxide.
65. Explain the term mixture.
A mixture is a combination of two or more substances that are not chemically combined and can be separated by physical means.
66. Define compound and give one example.
A compound is a substance formed when two or more elements combine chemically in fixed proportions. An example is carbon dioxide.
67. What is evaporation?
Evaporation is the process by which a liquid changes into vapour at its surface below its boiling point.
68. Define solubility.
Solubility is the maximum amount of solute that can dissolve in a given quantity of solvent at a specific temperature.
69. What is oxidation?
Oxidation is the process of gaining oxygen or losing electrons during a chemical reaction.
70. Define reduction.
Reduction is the process of losing oxygen or gaining electrons in a chemical reaction.
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