NECO Chemistry Past Questions And Answers

NECO Chemistry Past Questions And Answers

The National Examination Council (NECO) is a Nigerian examination body responsible for conducting national examinations for secondary school students. One of the subjects that NECO offers is Chemistry.

If you are a student who is preparing for the NECO Chemistry exam, then you need to be familiar with the past questions.

The past questions can give you an idea of the type of questions that you will be asked on the exam, and they can also help you to identify your weak areas.

In this blog article, I will provide you with a comprehensive guide to NECO Chemistry past questions and answers. I will discuss the following topics:

• How to find NECO Chemistry past questions

• How to use NECO Chemistry past questions to prepare for the exam

• FAQ about NECO Chemistry on Google

How to Find NECO Chemistry Past Questions

There are a few different ways to find NECO Chemistry past questions. One way is to purchase a past questions book from a bookstore. Another way is to download the past questions from the NECO website.

The NECO website has a section where you can download past questions for all of the subjects that NECO offers. The past questions are available in PDF format.

How to Use NECO Chemistry Past Questions to Prepare for the Exam

Once you have found the NECO Chemistry past questions, you can start using them to prepare for the exam. Here are a few tips on how to use the past questions effectively:

• Start by reading through the past questions. This will give you an idea of the type of questions that you will be asked on the exam.

• Pay attention to the different question types. The NECO Chemistry exam includes a variety of question types, such as multiple choice, fill in the blank, and essay questions.

• Make sure that you understand the answers to the past questions. If you don’t understand an answer, then you should research it further.

• Practice answering the past questions. This will help you to get used to the format of the exam and to improve your timing.

NECO Chemistry Past Questions And Answers:

NECO Chemistry Questions and Answers For Practice

1. The minimum amount of energy required for effective collisions between reacting particles is known
A) Activation energy
B) Bond energy
C) Kinetic energy
D) Potential energy

2. The bond formed between H2OH2O and H+H+ to form the hydroxonium H3O+H3O+ is
A) Dative
B) Covalent
C) Electrovalent
D) Ionic

3. An element XX forms the following oxides X2O,XOX2O,XO and XO2.XO2. This phenomenon illustrates the law of ________.
A) Conservation of mass
B) Definite proportion
C) Mass action
D) Multiple proportion

4.. How many moles of oxygen would contain 1.204×10241.204×1024 molecules?
NB: Avogadro’s constant (NA) =6.02×1023=6.02×1023
A) 1
B) 2
C) 3
D) 4

5. Which of the following statements about solids is correct?
A) Solid particles are less orderly than those of a liquid
B) Solid have lower densities than liquids
C) Solid particles have greater kinetic energies than those of liquids
D) Solid particles cannot be easily compressed

6. Which of the following apparatus can be used to measure a specific volume of a liquid accurately?
A) Beaker
B) Conical flask
C) Measuring cyclinder
D) Pipette

7. The general gas equation PVT=KPVT=K is a combination of
A) Boyle’s and Charles’ laws
B) Boyle’s and Graham’s laws
C) Charles’ and Graham’s laws
D) Dalton’s and Graham’s laws

8. The spreading of the scent of a flower in a garden is an example of?
A) Brownian motion
B) Diffusion
C) Osmosis
D) Tynadal effect

9. Propane and carbon (IV) oxide diffuse at the same rate because [H = 1.00, C = 12.0, O = 16.0]
Options
A) They are both gases
B) Their molecules contain carbon
C) They have the same relative molecular mass
D) Both are denser than air

1O. The energy which accompanies the addition of an electron to an isolated gaseous atom is
A) Atomization
B) Electronegativity
C) Electron affinity
D) Ionization

11. A sample of hard water contains some calcium sulphate and calcium hydrogen carbonate. The total hardness may therefore be removed by
A. boiling the water
B. adding excess calcium hydroxide
C. adding a calculated amount of calcium hydroxide
D. adding sodium carbonate
E. adding magnesium hydroxide

12. During the electrolysis of copper II sulphate between platinum electrodes, if litmus solution is added to the anode compartment,
A. the litmus turns blue but no gas is evolved
B. the litmus turns blue and oxygen is evolved
C. the litmus turns blue and hydrogen is evolved
D. the litmus turns red and oxygen is evolved
E. the litmus turns red and then becomes colourless

13. The reaction between an organic acid and an alcohol in the presence of an acid catalyst is known as;
A. saponification
B. dehydration
C. esterification
D. hydrolysis
E. hydration

14. The IUPAC names of the compounds CH3COOH and CH2=CH2 are respectively;
A. acetic acid and ethane
B. ethanoic acid and ethene
C. methanoic acid and ethylene
D. ethanol and ethene
E. acetic acid and ethylene

15. If 30cm3 of oxygen diffuses through a porous pot in 7 seconds, how long will it take 60cm3 of chlorine to diffuse through the same pot, if the vapour densities of oxygen and chlorine are 16 and 36 respectively?
A. 9.3 sec
B. 14 sec
C. 21 sec
D. 28 sec
E. 30.3 sec

16. When heat is absorbed during a chemical reaction, the reaction is said to be
A. thermodynamic
B. exothermic
C. isothermal
D. endothermic
E. thermostatic

17. When large hydrocarbon molecules are heated at high temperature in the presence of a catalyst to give smaller molecules, the process is known as
A. disintegration
B. polymerization
C. cracking
D. degradation
E. distillation

18. The pH of four solutions W, X, Y, Z are 4, 6, 8, 10 respectively, therefore
A. none of these solutions is acidic
B. the pH of Y is made more acidic by addition of distilled water
C. Z is the most acidic solution
D. W is the most acidic solution
E. X is neutral

19. When each of the nitrates of Potassium, Magnesium and iron is heated,
A. all the nitrates decompose to their oxides
B. the nitrate of magnesium gives the nitrite and oxygen
C. the nitrates of iron magnesium and iron give the oxides
D. the nitrate of iron gives the nitrite and oxygen
E. the nitrate of the magnesium is not decomposed

2O. Which of the following metals cannot replace hydrogen from water or steam?
A. Sodium
B. Magnesium
C. Iron
D. Calcium
E. Copper

21. small quantity of solid ammonium chloride (NH4Cl) was heated gently in a test tube, the solid gradually disappears to produce two gases. Later, a white cloudy deposit was observed on the cooler part of the test tube. The ammonium chloride is said to have undergone
A. distillation
B. sublimation
C. precipitation
D. evaporation
E. decomposition

22. Elements P, Q, R, S have 6, 11, 15, 17 electrons respectively, therefore,
A. P will form an electrovalent bond with R
B. Q will form a covalent bond with S
C. R will form an electrovalent bond with S
D. Q will form an electrovalent bond with S
E. Q will form a covalent bond with R

23. An element X forms the following compounds with chlorine; XCl4, XCl3, XCl2. This illustrates the
A. law of multiple proportions
B. law of chemical proportions
C. law of simple proportions
D. law of conservation of mass
E. law of definite proportions

24. The oxidation state of chlorine in potassium chlorate is
A. +1
B. +2
C. +3
D. +5
E. +7

25. 10 When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are;
A. nitrogen and carbondioxide
B. the rare gases
C. nitrogen and oxygen
D. nitrogen and the rare gases
E. nitrogen, carbondioxide and the rare

26. Which of the following statements is NOT correct?
A. The average kinetic energy of a gas is directly proportional to its temperature
B. At constant tempearture, the volume of a gas increases as the pressure increases
C. The pressure of a gas is inversely proportional to its volume
D. The temperature of a gas is directly proportional to its volume
E. The collisions of molecules with each other are inelastic

27. Zinc Oxide is a
A. Basic Oxide
B. Acidic Oxide
C. Amphoteric Oxide
D. Neutral Oxide
E. Reactive Oxide

28. When sodium chloride and metallic sodium are each dissolved in water
A. both processes are exothermic
B. both processes are endothermic
C. the dissolution of metallic sodium is endothermic
D. the dissolution of metallic sodium is exothermic
E. the dissolution of sodium chloride is explosive

29. The periodic classification of elements is an arrangement of the elements in order of their
A. Atomic Weights
B. Isotopic Weights
C. Molecular Weights
D. Atomic Numbers
E. Atomic Masses

3O. In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?
A. 5cm3
B. 10cm3
C. 20cm3
D. 25cm3
E. 50cm3

FAQs

• Where can I find NECO Chemistry past questions?

• How do I use NECO Chemistry past questions to prepare for the exam?

• What are the different question types on the NECO Chemistry exam?

• What is the best way to study for the NECO Chemistry exam?