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 731:

  

  Choose the correct answer from the options above.

  When Fehling's solution is added to two isomeric carbonyl compounds X and Y with the molecular formula C ₅H ₁₀O, compound X gives a red precipitate while Y does not react. It can be inferred that X is

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is B .
• Question 732:

  Which of the following can be obtained by fractional distillation? 

  Options:
  A) Nitrogen from liquid air
  B) Sodium Chloride from sea water
  C) Iodine from solution of Iodine in carbon tetrachloride
  D) Sulphur from the solution of sulphur in carbon disulphide
  Show Answer
  The correct answer is A .
• Question 733: Which of the following terms indicates the number of bonds that can be formed by an atom? Options:
  A) Oxidation number
  B) Valence
  C) Atomic number
  D) Electronegativity
  Show Answer
  The correct answer is B .
• Question 734: The mass number of an atom is? Options:
  A) the number of electrons in the atom
  B) the number of protons in the nucleus of the atom
  C) the number of neutrons in the nucleus of the atom
  D) the sum of numbers of electrons and protons inthe atom
  E) the sum of numbers of proton and neutrons in the nucleus of the atom
  Show Answer
  The correct answer is E .
• Question 735: Which of the following is used to study the arrangement of particles in crystal lattices? Options:
  A) Alpha-particles
  B) Beta-particles
  C) Gamma-rays
  D) X-rays
  Show Answer
  The correct answer is D .
• Question 736:

  Pure sulphuric acid is a liquid of 1:84 density. What volume of it would be required to prepare 250 cm³ of 2.0 M solution?

  (H = 1, S = 32, O = 16)

  Options:
  A) 2.00
  B) 2.66
  C) 3.00
  D) 3.66
  E) 4.00
  Show Answer
  The correct answer is B .
• Question 737: The salt formed from a reaction between citric acid and sodium hydroxide in solution will be Options:
  A) acidic
  B) basic
  C) complex
  D) neutral
  Show Answer
  The correct answer is B .
• Question 738:

  The shapes of water, ammonia, carbon (iv) oxide and methane are respectively

  Options:
  A) linear, tetrahedral, angular and pyramidal
  B) angular, pyramidal, linear and tetrahedral
  C) pyramidal, linear, tetrahedral and angular
  D) tetrahedral, angular, pyramidal and linear
  Show Answer
  The correct answer is B .
• Question 739: Which of the following compounds gives a yellow residue when heated and also reacts with aqueous sodium hydroxide to give a white gelatinous precipitate soluble in excess sodium hydroxide solution? Options:
  A) (NH₄)CO₃
  B) ZnCO₃
  C) Al₂(SO₄)₃
  D) PbCO3
  Show Answer
  The correct answer is B .
• Question 740: The gas that will form a white precipitate with acidified silver trioxonitrate (v) is Options:
  A) NH₃
  B) SO₂
  C) CO₂
  D) HCL
  Show Answer
  The correct answer is D .