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 1201: A change in the temperature of a saturated solution disturbs the equilibrium between the Options:
  A) Undissolved solute and the solvent
  B) Dissolved solute and the solvent
  C) Dissolved solute and the undissolved solute
  D) Dissolved solute and the solution
  Show Answer
  The correct answer is C .
• Question 1202:

  How many atoms are present in 6.0g of magnesium? [Mg = 24, N.A = 6.02 x 10 ${}^{23}$mol]

  Options:
  A) 1.20 x 10${}^{22}$
  B) 2.4 x 10${}^{22}$
  C) 1.51 x 10${}^{22}$
  D) 3.02 x 10${}^{22}$
  Show Answer
  The correct answer is C .
• Question 1203: Some products of destructive distillation of coal are Options:
  A) carbon (IV) oxide and ethanoic acid
  B) trioxocarbonate (IV) acid and methanoic acid
  C) producer gas and water gas
  D) coke and ammonia liquor
  Show Answer
  The correct answer is D .
• Question 1204:

  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 1205: The oxidation state of oxygen in tetraoxosulphate (VI) acid is Options:
  A) -4
  B) -2
  C) +4
  D) -8
  Show Answer
  The correct answer is B .
• Question 1206:

  Sodium reacts vigorously with water to produce

  Options:
  A) Sodium chloride (NaCl) and oxygen gas (O2)
  B) Sodium nitrate (NaNO3) and water (H2O)
  C) Sodium hydroxide (NaOH) and hydrogen gas (H2)
  D) Sodium oxide (Na2O) and hydrogen gas (H2)
  Show Answer
  The correct answer is C .
• Question 1207:

  An organic compound with a vapour density 56.5 has the following percentage composition:C =53.1% N = 12.4%, O = 28.3%, H = 6.2%. The molecular formula of the compound is

  Relative atomic masses: N = 14, O = 16, C = 12, H = 1 )

  Options:
  A) C₃H₆O₂N
  B) C₅H₆O₂N
  C) (C₅H₇O₂N)_1/2
  D) C₅H₇O₂N
  E) (C₅H₇O₂N)₂
  Show Answer
  The correct answer is D .
• Question 1208: Which of the following processes takes place during electrolysis? Options:
  A) Positive ions are discharged at the anode bby gaining sufficient electrons to become neutral
  B) Negative ions are dicharged at the anode by gaining suficient electrons to become neutral
  C) Positive ions are discharged at the anode by losing sufficient electrons to become neutral
  D) Negative ions are discharge at the anode by losing sufficient electrons to become neutral
  E) Nothing happens
  Show Answer
  The correct answer is D .
• Question 1209: Which of the following types of bonding does not involve the formation of new substances? Options:
  A) Metallic
  B) covalent
  C) co-ordinate
  D) electrovalent
  Show Answer
  The correct answer is A .
• Question 1210: The greater the different in electronegativity between bonded atoms, the? Options:
  A) lower the polarity of the bond
  B) higher the polarity of the bond
  C) weaker the bond
  D) higher the possibility of the substance formed being a molecule
  Show Answer
  The correct answer is C .