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 1601: When chlorine gas is passed into a solution of sulphur dioxide? Options:
  A) sulphur dioxide is reduced to sulphur
  B) the chlorine is oxidized to hydrochloric acid
  C) dilute sulphuric acid and hydrochloric acid are produced
  D) Hydrochloric acid and sulphur are produced
  E) sulphur trioxide is the only product
  Show Answer
  The correct answer is C .
• Question 1602:

  The general formula for the Alkanals is?

  Options:
  A) R${}_2$CO
  B) RCHO
  C) ROH
  D) RCOOR
  Show Answer
  The correct answer is B .
• Question 1603: Carbohydrates are large molecules with the molecular formula C _x (H₂O)_y. In which of the following pairs is x not equal to y? Options:
  A) glucose and starch
  B) maltose and starch
  C) sucrose and fructose
  D) maltose and starch
  Show Answer
  The correct answer is A .
• Question 1604: In the laboratory preparation of chlorine from concentrated hydrochloric acid in the presence of potassuim tetraoxomanganate(VII) the produced is dried by passing it through Options:
  A) Concentrated tetraoxosulphate (VI) acid
  B) Anhydrous calcium chloride
  C) Calcium oxide
  D) Sodium hydroxide
  Show Answer
  The correct answer is A .
• Question 1605: 2-methylprop-1-ene is an isomer of Options:
  A) but-2-ene
  B) pent-1-ene
  C) 2-methylbut-2-ene
  D) 2-methylbut-1-ene
  Show Answer
  The correct answer is A .
• Question 1606: The property used in obtaining oxygen and nitrogen industrially from air is the? Options:
  A) boiling point
  B) density
  C) rate of diffusion
  D) solubility
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  The correct answer is A .
• Question 1607: A cycloalkane with the molecular formula C₅H₁₀ has ? Options:
  A) one isomer
  B) two isomers
  C) three isomers
  D) four isomers
  Show Answer
  The correct answer is C .
• Question 1608: The relationship between the velocity (U) of gas molecules and their relative molecular mass (M) is shown by the equation Options:
  A) U = (kM)$\frac{1}{2}$
  B) U = (kM)²
  C) U = $\sqrt{k}m$
  D) U = ($\frac{k}{m}$)${}^{\frac{1}{2}}$
  Show Answer
  The correct answer is C .
• Question 1609: Sodium and potassium belong to the same group of the Periodic Table. This is because? Options:
  A) both are metals
  B) both are soft and lighter than water
  C) both form cations by losing electrons
  D) both have identical electronic configuration
  E) both react with water vigorously
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  The correct answer is D .
• Question 1610: The most abundant element on the earth's crust is Options:
  A) nitrogen
  B) hydrogen
  C) oxygen
  D) flourine
  Show Answer
  The correct answer is C .