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 1551: Which of the following ion’s requires the quantity of electricity for discharge at an electrode Options:
  A) 2.0 mole of Q3⁺
  B) 2.5 mole of R2⁺
  C) 3.0 mole of T^-
  D) 4.0 mole of Y^-
  Show Answer
  The correct answer is A .
• Question 1552: Which of these require crystallization most? Options:
  A) Drug making
  B) Cement making
  C) Paint making
  D) Perfume making
  Show Answer
  The correct answer is A .
• Question 1553: The basic assumption in the kinetic theory of gases that the collisions of the gaseous molecules are perfectly elastic implies that the Options:
  A) forces of attraction and repulsion are in equilibrium
  B) gaseous molecules can occupy any available space
  C) gaseous molecules will continue their motion indefinitely
  D) gases can be compressed
  Show Answer
  The correct answer is C .
• Question 1554: A small quantity of solid ammonium chloride (NH4Cl) texted gently in a test tube, the solid gradually disappear produce two gases. Later, a white cloudy deposit was absence on the cooler part of the test tube. The ammonium chloride is to have undergo Options:
  A) distillation
  B) sublimation
  C) precipitation
  D) evaporation
  Show Answer
  The correct answer is B .
• Question 1555: Which of the following reactions is correct as as written? Options:
  A) FeCl₂ + 3NH₄OH → Fe(OH)₃ + 3NH₄Cl
  B) Pb₂O₃ + 4HCl → PbCl₂ + 2H₂O
  C) PbNO₃ + H₂S → PbS + 2HNO₃
  D) NaOH + H₂SO₄ → NaHSO₄ +H₂O
  E) 2NH₄NO₃ → N₂ + 2H₂O
  Show Answer
  The correct answer is D .
• Question 1556:

  What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

  Options:
  A) 8.0g
  B) 16.0g
  C) 36.0g
  D) 72.0g
  Show Answer
  The correct answer is D .
• Question 1557:

  ZnO_(s) + CO_(g) → Zn_(s) + CO_2(g)

  In the reaction above, Zinc has been

  Options:
  A) decomposed
  B) displaced
  C) oxidized
  D) reduced
  Show Answer
  The correct answer is D .
• Question 1558: 9.8g of solid potassium chlorate (KCIO₃) were added to 40 cm³ of water and heated to dissolve all the solid. As he solution cooled, crystals of potassium chlorate started forming at 60°C. The solubility of potassium chlorate at 66°C is therefore? Options:
  A) 24.5 mole per dm³
  B) 0.2 mole per dm³
  C) 10.0 mole per dm³
  D) 20.0 mole per dm³
  E) 2.0 mole per dm³
  Show Answer
  The correct answer is E .
• Question 1559: Calculate the relative molecular mass of Limestone CaCO3, (Ca = 40, C =12, O = 16) Options:
  A) 56
  B) 100
  C) 76
  D) 90
  Show Answer
  The correct answer is B .
• Question 1560: When each of the nitrates of Potassium, Magnesium and iron is heated, Options:
  A) all the nitrates decompose to their oxides
  B) the nitrate of magnesium gives the nitrite and oxygen
  C) the nitrates of iron magnesium and iron give the oxides
  D) the nitrate of iron gives the nitrite and oxygen
  E) the nitrate of the magnesium is not decomposed
  Show Answer
  The correct answer is C .