NECO Chemistry Past Questions and Answers | Theory and Objectives –Download PDF.

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NECO Chemistry Past Questions and Answers | Theory and Objectives –Download PDF.

The National Examination Council of Nigeria (NECO) Examination is around the corner. This article provides the readers with the information on how to download NECO Chemistry Past Questions and Answers. NECO Chemistry Questions are essential for you to know if you want to pass the NECO SSCE Chemistry Exams 2021.

NECO Past Questions and Answers

NECO Past Questions and Answers for all Subjects

The NECO Chemistry past questions and answers is a compiled material in PDF that contains past questions from NECO Chemistry Exams of previous years. The material comes with answers and is easily downloadable.

You can download the materials here. The instructions on how to download the NECO Chemistry can be found below. You are expected to follow the instructions in order for you to succeed. The material does not only contain information on NECO Chemistry Questions and answers but how to pass exams as well. You can see this article on the 21 indispensable steps to pass any exams with high grade.

Download also: WAEC past Questions and Answers.

NECO Chemistry Sample Questions and Answers

The following NECO Chemistry questions are questions to expect in the 2021 NECO examination.

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]
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

How to Download NECO Chemistry past Questions and Answers

Here are the instructions to be followed in order to download the NECO Chemistry Questions and answers without any issue. Please follow our instructions and guide very well.

The cost of the newly updated NECO Past Questions and Answers is 2,000.00 naira only for One Subject e.g

  • Use of English 1000 naira
  • Biology 1000 naira
  • Chemistry 1000 naira
  • Physics 1000 naira

See The Payment Detail Below.

To get NECO Past Questions and Answers follow the steps below.

Pay into the account below.

Account Details

Account Number0318379097

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(1) Depositors name,

 (2) Teller number,

(3) Amount paid to 07063986527 on whatsapp or

The purchased NECO Past Questions and Answer will be uploaded immediately into your email address within the next 24 hours.

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Tips on How to Pass NECO Examination 2021

If you want to Past the NECO Examination this year, you will need to follow the instructions below.

  • Practice daily with NECO Past Questions and Answers
  • Write out your subjects, the dates and time.
  • Engage in general revision few days to the examination and dwell more on the subjects you find difficult.
  • Focus on only your first paper a week to the exam. This would make it sweet and you will have energy to read for other papers.
  • Don’t read any other subject when it is two days to a particular subject.
  • When you have two papers that are separated by only one day, read the second one first before going to the subject you have first.
  • Ensure to be in the NECO examination venue at least two hours to the examination so that you would be balanced.
  • Try to be up to date in cases of changes in the timetable.
  • Have a personal copy of the NECO timetable and syllabus.
  • Go through your timetable daily so that you don’t miss any paper.
  • Don’t go to the hall when you are not having paper that day.

Disclaimer: Please note these are not the actual questions and answers that you will find in the NECO Examination this year, but they are the likely questions. to get the actual NECO Past Questions and answers, please call 07063986527.

Download Actual NECO Past Questions and Answers.

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