Chemistry Exam Past Questions and Answers | JAMB, WAEC and NECO

Chemistry is the study of the substances that make up matter. It looks at their properties, how they react with each other, and how these reactions can create new substances.

• Question 1: Potassium tetraoxomanganate (VII) is often added to impure water to? Options:
  A) reduce organic impurities
  B) reduce inorganic impurities
  C) destroy bacteria and algae
  D) remove permanent hardness
  Show Answer
  The correct answer is C .
• Question 2: When calcium oxide is heated with carbon, the oxide will Options:
  A) be converted to carbide
  B) be converted to the trioxocarbonate (IV) salt
  C) decompose to the metal
  D) melt,producingg carbon (IV) oxide
  Show Answer
  The correct answer is A .
• Question 3:

  

  The option above shows the PH changes for the titration of a

  Options:
  A) strong acid versus strong base
  B) weak acid versus strong base
  C) strong acid versus weak base
  D) weak acid versus weak base
  Show Answer
  The correct answer is A .
• Question 4: How many cations will be produced from a solution of potassium aluminium tetraoxosulphate (VI)? Options:
  A) 3
  B) 4
  C) 1
  D) 2
  Show Answer
  The correct answer is D .
• Question 5: When a little brine was added to a metal nitrate a white precipitate was formed which first turned violet and then black on exposure to ai. The metal nitrate is therefore? Options:
  A) sodium nitrate
  B) mercuric nitrate
  C) lithium nitrate
  D) silver nitrate
  E) potassium nitrate
  Show Answer
  The correct answer is D .
• Question 6: One note of a hydrocarbon 36g of carbon and its density is 20. The structure of hydrocarbon is (organic chemical) Options:
  A) CH3C = CH
  B) CH3CH = CH2
  C) CH3CH2C = CH
  D) CH33CH2CH3
  Show Answer
  The correct answer is A .
• Question 7:

  On which of the following is the solubility of a gaseous substance dependent? 

  I. Nature of solvent 

  II. Nature of solute 

  III. Temperature 

  IV. Pressure

  Options:
  A) I, II, III and IV
  B) I and II only
  C) II only
  D) I, III and IV only
  Show Answer
  The correct answer is D .
• Question 8: Which of the following acts as both a reducing and an oxidizing agent? Options:
  A) H₂
  B) SO₂
  C) H₂S
  D) C
  Show Answer
  The correct answer is B .
• Question 9:

  Who proposed the planetary model of the atom with electrons orbiting the nucleus?

  Options:
  A) Erwin Schrödinger
  B) Ernest Rutherford
  C) Niels Bohr
  D) J.J. Thomson
  Show Answer
  The correct answer is C .
• Question 10: Alloys are best prepared by Options:
  A) electroplating
  B) Arc-welding
  C) reducing and mixture of their metallic
  D) cooking a molten of the metals
  Show Answer
  The correct answer is D .