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 1221:

  The lanthanides and actinides are located in which block of the periodic table?

  Options:
  A) P-block
  B) S-block
  C) F-block
  D) D-block
  Show Answer
  The correct answer is C .
• Question 1222: An isotope has an atomic number of 17 and a mass number of 36. Which of the following gives the correct number of neutrons and protons in an atom of the isotope? Options:
  A) Neutrons 53, Protons 17
  B) Neutrons 17, Protons 36
  C) Neutrons 19, Protons 17
  D) Neutrons 36, Protons 17
  Show Answer
  The correct answer is C .
• Question 1223: The highest rate of production of carbon (lV) oxide can be achieved using Options:
  A) 0.05 mol ^-3HCI and 5g powdered CaCO₃
  B) 0.05 mol ^-3HCI and 5g lump CaCO₃
  C) 0.10 mol ^-3HCI and 5g powdered CaCO₃
  D) 0.025 mol ^-3HCI and 5g powdered CaCO₃
  Show Answer
  The correct answer is C .
• Question 1224:

  

  In the diagram above, X is the ``

  Options:
  A) enthalpy
  B) enthalpy change
  C) activation energy
  D) activated complex
  Show Answer
  The correct answer is B .
• Question 1225: Which of the following does NOT contain aluminium as component? Options:
  A) Over-head cables
  B) Duralumin
  C) Container for caustic soda
  D) Container for nitric acid
  Show Answer
  The correct answer is D .
• Question 1226: The number of atoms of chlorine present in 5.85g of NaCl is [Avogaro's Number = 6.02 x 10²³] Options:
  A) 6.02 x 10²²
  B) 5.85 x 10²³
  C) 6.02 x 10²³
  D) 5.85 x 10²⁴
  Show Answer
  The correct answer is A .
• Question 1227:

  ${}_{11}^{11}Na{+}_0^{1}n{\to }_{11}^{24}Na$

  The reaction above is an example of

  Options:
  A) nuclear fission
  B) nuclear fusion
  C) artificial transmutation
  D) beta decay
  Show Answer
  The correct answer is C .
• Question 1228: The phenomenon whereby sodium trioxocarbonate (IV) decahydrate loses some of its water of crystallization on exposure to the atmosphere is known as? Options:
  A) deliquescene
  B) hygroscopy
  C) effervescence
  D) efflorescence
  Show Answer
  The correct answer is D .
• Question 1229: 90.0g of MgCI₂ was placed in 50.0cm³ of water to give a saturated solubility of the salt is 8.0 mol dm³ at the same temperature, what is the mass of the salt left undissolved at the given temperature?(Mg = 24, Cl = 35.5) Options:
  A) 52.0g
  B) 58.5g
  C) 85.5g
  D) 88.5g
  Show Answer
  The correct answer is A .
• Question 1230: Which of the following compounds is a neutral oxide? Options:
  A) Carbon (IV) oxide
  B) Sulphur (Vl) oixide
  C) Sulphur (IV) oxide
  D) Carbon (ll) oxide
  Show Answer
  The correct answer is D .