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 791: Which of the following is NOT used as a raw material in the Solvay process? Options:
  A) Ammonia
  B) Sodium chloride
  C) Calcium trioxocarbonate (IV)
  D) Sodium trioxocarbonate (IV)
  Show Answer
  The correct answer is D .
• Question 792: How many grams of HBr would exactly be required to react with 2 g of propyne? (C =12, H=1, Br = 80) Options:
  A) 4. 1 g
  B) 6. 1 g
  C) 8. 1g
  D) 16.2g
  Show Answer
  The correct answer is C .
• Question 793:

  NH₄Cl_(s) ↔ NH_3(g) + HCL_(g)

  The reaction above can only attain equilibrium if

  Options:
  A) a gaseous reactant is added
  B) one of the products is removed
  C) it is in a closed system
  D) it is an open system
  Show Answer
  The correct answer is C .
• Question 794:

  What is the mass percentage of carbon (C) in methane (CH4)? (The molar mass of carbon is approximately 12 g/mol.)

  Options:
  A) 25%
  B) 12%
  C) 75%
  D) 50%
  Show Answer
  The correct answer is C .
• Question 795: The empirical formula of an oxide of nitrogen containing 30.4 per cent of nitrogen is (N=14.0,O=16.0) Options:
  A) N₂O₂
  B) NO
  C) NO₂
  D) N₂O
  E) N₂O₃
  Show Answer
  The correct answer is C .
• Question 796: When ethanol is heated with excess concentrated sulphuric acid, the ethanol is? Options:
  A) oxidized to ethene
  B) polymerized to polyethene
  C) dehydrated to ethene
  D) dehydrated to ethyne
  Show Answer
  The correct answer is C .
• Question 797:

  What is the IUPAC name for the following compound? HC$\equiv$CCH${}_3$

  Options:
  A) Acetylene
  B) Methyl acetylene
  C) Butanol
  D) Decanoic acid
  Show Answer
  The correct answer is B .
• Question 798: The nucleus of the isotope tritium, contains? Options:
  A) two neutrons with no protons
  B) one neutron and one protons
  C) two neutrons and one proton
  D) two neutrons, one proton and one electron
  Show Answer
  The correct answer is C .
• Question 799:

  Using the metal activity series, the metal that can liberate hydrogen gas from steam is?

  Options:
  A) iron
  B) copper
  C) tin
  D) lead
  Show Answer
  The correct answer is A .
• Question 800:

  A small quantity of solid ammonium chloride (NH₄Cl) was heated gently in a test tube, the solid gradually disappears to produce two gases. Later, a white cloudy deposit was observed on the cooler part of the test tube. The ammonium chloride is said to have undergone

  Options:
  A) distillation
  B) sublimation
  C) precipitation
  D) evaporation
  E) decomposition
  Show Answer
  The correct answer is B .