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 1811:

  The size (diameter) of five elements are in the order R < T < W < X < Y, Y being the largest. If each atom has an electron situated on its circumference, and neglecting other factors, which of the atoms will lose its electron most reluctantly?

  Options:
  A) R
  B) T
  C) W
  D) X
  E) Y
  Show Answer
  The correct answer is A .
• Question 1812: The enzymes responsible for converting sucrose into two simple isomeric sugars is Options:
  A) maltase
  B) amylase
  C) invertase
  D) lactase
  Show Answer
  The correct answer is C .
• Question 1813: An example of aliphatic unsaturated hydrocarbon is Options:
  A) pentane
  B) butanol
  C) propene
  D) benzene
  Show Answer
  The correct answer is C .
• Question 1814: Which of the following statements is true of sulphur (IV) oxide? Options:
  A) It forms tetraoxosulphate (VI) acid with water
  B) It is an odourless gas
  C) It is an acid hybride
  D) It forms white precipitate with acidified barium chloride
  Show Answer
  The correct answer is C .
• Question 1815:

  The sulphide that is commonly used in coating electric fluorescent tubes is?

  Options:
  A) iron(ii)Sulphide
  B) tin(ii)sulphide
  C) Zinc Sulphide
  D) lead(iv) Sulphide
  Show Answer
  The correct answer is C .
• Question 1816: Water has the ability to dissolve almost all substance because its molecules has a structure with Options:
  A) one positive end and one neutral end
  B) one positive end and one negative end
  C) two negative ends
  D) two positive ends
  Show Answer
  The correct answer is B .
• Question 1817: A major process involved in the softening of hard water is the? Options:
  A) conversation of a soluble calcium salt to its trioxoncarbonate (lV)
  B) decomposition of calcium rioxocarbonate (lV)
  C) conversion of an insoluble calcium salts to its trioxocarbonate (lV)
  D) oxidation of calcium atoms to its ions
  Show Answer
  The correct answer is A .
• Question 1818:

  

  The functional groups present in the compound above are

  Options:
  A) Alkene and halo-group
  B) Hydroxyl and chloro-group
  C) Alkene and chloro-group
  D) Hydroxyl and halo-group
  Show Answer
  The correct answer is B .
• Question 1819:

  A chemical process in which there is a gain of electrons is known as?

  Options:
  A) Sublimation
  B) Reduction
  C) Oxidation
  D) Distillation
  Show Answer
  The correct answer is B .
• Question 1820: A sample of orange juice is found to have a PH of 3.80. What is the concentration of the hydroxide ion in the juice? Options:
  A) 1.6 $\times$ 10^-4
  B) 6.3 $\times$ 10^-11
  C) 6.3 $\times$ 10^-4
  D) 1.6 $\times$ 10^-11
  Show Answer
  The correct answer is B .