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 611:

  SO${}_2$ + O${}_2$ 2SO${}_3$

  In the reaction above, the most suitable catalyst is?

  Options:
  A) chromium(vi)oxide
  B) iron(iii)oxide
  C) copper(i)oxide
  D) vanadium(v)oxide
  Show Answer
  The correct answer is D .
• Question 612: Weighed salts Y and Z were left exposed in the laboratory overnight. In the morning Y had gained weight, and Z had become liquid. What conclusion could be drawn about the nature of the two salts? Options:
  A) Z is efflorescent
  B) Y and Z are efflorescent
  C) Y and Z are deliquescent
  D) Y and Z are hygroscopic
  E) Y is deliquescent
  Show Answer
  The correct answer is C .
• Question 613: On exposure to the atmosphere, a hydrated salt loses its water of crystallization to become anhydrous. This phenomenon is referred to as Options:
  A) efflorescence
  B) diliquescence
  C) hygroscopy
  D) hydrolysis
  Show Answer
  The correct answer is A .
• Question 614:

  Which of the following is a primary constituent of crude oil?

  Options:
  A) Pentane
  B) Ethanol
  C) Heptane
  D) Methane
  Show Answer
  The correct answer is D .
• Question 615: In the reaction 1O^-₃ + 5l^- + 6H⁺ → 31₂ + 3H₂O, the oxidizing agent is? Options:
  A) H⁺
  B) l^-
  C) 1O^-
  D) l₂
  Show Answer
  The correct answer is C .
• Question 616: 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 617: The pollutants that are likely to be present in an industrial environment are? Options:
  A) H₂S,SO₂ and oxides of nitrogen
  B) NH₃, HCI and CO
  C) CO₂, NH₃ and H₂S
  D) dust, NO and CI₂
  Show Answer
  The correct answer is A .
• Question 618:

  Which noble gas is radioactive and is produced as a decay product of uranium and thorium?

  Options:
  A) Argon
  B) Krypton
  C) Radon
  D) Neon
  Show Answer
  The correct answer is C .
• Question 619:

  

  The above orbital diagram shown the electronic configuration of

  Options:
  A) chlorine
  B) nitrogen
  C) calcium
  D) neon
  Show Answer
  The correct answer is B .
• Question 620:

  Which of the following gases contains the least number of atoms at s.t.p?

  Options:
  A) 1 mole of butane
  B) 4 moles of chlorine
  C) 3 moles of ozone
  D) 7 moles of argon
  Show Answer
  The correct answer is A .