2025 NECO GCE Chemistry Past Questions and Answers |Guide

Introduction

Many students preparing for the exam are searching for 2025 NECO GCE Chemistry past questions, complete NECO GCE Chemistry questions and answers 2025, and reliable NECO GCE Chemistry practice questions to strengthen their NECO GCE Chemistry exam preparation.This article provides a complete guide to NECO GCE Chemistry practice questions and answers, highlighting exam structure, sample questions, solutions, and study tips to help you excel.

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Objectives of 2025 NECO GCE Chemistry Past Questions and exam aims to:

• Test candidates’ knowledge of fundamental chemical principles.

• Assess the ability to apply concepts to real-life situations.

• Evaluate candidates’ problem-solving skills through theory and calculations.

• Examine experimental skills and practical knowledge.

The ultimate goal is to prepare students for higher studies in science and technology fields such as medicine, engineering, agriculture, and environmental sciences.

NECO GCE Chemistry 2025 Exam Structure

The exam is divided into three main parts:

1. Paper I (Objective):

   • 50 multiple-choice questions.

   • Covers general Chemistry knowledge across the syllabus.

   • Designed to test speed and accuracy.

2. Paper II (Essay):

   • Structured and long-answer questions.

   • Candidates are expected to provide detailed explanations, calculations, and sometimes diagrams.

3. Paper III (Practical):

   • Tests laboratory skills, observation, and accurate recording of data.

   • Includes titration, qualitative analysis, and simple experiments.

Sample Practice Questions and Answers for NECO GCE Chemistry 2025

Section A – Objective Questions

1. Which gas is used in the Haber process for ammonia production?
A. Nitrogen and oxygen
B. Nitrogen and hydrogen
C. Carbon dioxide and nitrogen
D. Oxygen and hydrogen
Answer: B. Nitrogen and hydrogen

2. The process by which a liquid changes directly to vapour at all temperatures is called:
A. Condensation
B. Evaporation
C. Sublimation
D. Fusion
Answer: B. Evaporation

3. Which of the following is a noble gas?
A. Oxygen
B. Argon
C. Nitrogen
D. Hydrogen
Answer: B. Argon

4. What is the oxidation state of manganese in KMnO₄?
A. +2
B. +4
C. +6
D. +7
Answer: D. +7

5. Which of the following acids is used in the manufacture of fertilizers?
A. Acetic acid
B. Nitric acid
C. Carbonic acid
D. Ethanoic acid
Answer: B. Nitric acid

Section B – Essay Questions

Question 1:
Write balanced equations for the following reactions:

• (a) Neutralization of H₂SO₄ with NaOH.

• (b) Thermal decomposition of calcium trioxocarbonate (IV).

Answer:

• (a) H₂SO₄ + 2NaOH → Na₂SO₄ + 2H₂O

• (b) CaCO₃ (s) → CaO (s) + CO₂ (g)

Question 2:
Calculate the molar concentration of NaOH if 25 cm³ of it neutralizes 20 cm³ of 0.1M HCl.

Solution:
Reaction: NaOH + HCl → NaCl + H₂O
Moles of HCl = M × V = 0.1 × 20/1000 = 0.002 mol
From the equation, mol ratio NaOH : HCl = 1 : 1
Moles of NaOH = 0.002 mol
Concentration = moles / volume = 0.002 / (25/1000) = 0.08 M

Question 3:
State two differences between ionic and covalent compounds.

Answer:

• Ionic compounds conduct electricity in molten or aqueous states, covalent compounds generally do not.

• Ionic compounds have high melting points, covalent compounds have relatively low melting points.

Question 4:
Explain why aluminium is used in making cooking utensils.

Answer:

• It is a good conductor of heat.

• It is light but strong.

• It resists corrosion due to the formation of a protective oxide layer.

Section C – Practical Sample Question

Experiment: A solution of HCl is titrated against NaOH using methyl orange indicator.

• Initial burette reading = 0.00 cm³

• Final burette reading = 24.50 cm³

Question: What is the volume of acid used?

Answer:
Volume = Final – Initial = 24.50 – 0.00 = 24.50 cm³

Key Topics to Cover in NECO GCE Chemistry 2025

To prepare effectively, focus on:

1. Physical Chemistry – Gas laws, thermodynamics, chemical kinetics, equilibrium.

2. Inorganic Chemistry – Periodic table, transition metals, acids, bases, and salts.

3. Organic Chemistry – Hydrocarbons, alcohols, carboxylic acids, esters, polymers.

4. Industrial Chemistry – Fertilizer production, soap and detergents, petroleum refining.

5. Practical Chemistry – Titrations, qualitative analysis, flame tests, laboratory safety.

Study Tips for Passing NECO GCE Chemistry 2025

1. Practice past questions regularly to understand the exam format.

2. Memorize key reactions and equations, not just their names.

3. Understand gas laws and stoichiometry, as they are frequently tested.

4. Draw diagrams neatly when required, especially in organic chemistry.

5. Master practicals by practicing titration and qualitative analysis techniques.

6. Use the NECO GCE Chemistry 2025 syllabus to guide your study schedule.

Why Practicing with Past Questions is Important

• Builds familiarity with exam patterns.

• Improves time management.

• Helps identify weak areas for improvement.

• Provides confidence before the actual exam.

For example, students who repeatedly solve NECO GCE Chemistry past questions and answers 2025 are better prepared to tackle both objective and essay papers effectively.

Conclusion

The 2025 NECO GCE Chemistry examination requires focus, practice, and smart preparation. By studying with Chemistry past questions and answers, practicing sample objectives and essays, and reviewing practical experiments, students can boost their chances of success. Use this guide as a companion for your NECO GCE Chemistry practice questions, and remember that consistent effort is the key to excelling in this subject.

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Disclaimer

This content is strictly for educational and revision purposes only. It does not encourage examination malpractice. Students are advised to use these NECO GCE Chemistry past questions and answers 2025 responsibly in preparing for their exams.