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 21: What volume of 0.5 MH₂SO₄ will exactly neutralize 20cm³ of 0.1 MNaOH Solution? Options:
  A) 2.0cm³
  B) 5.0cm³
  C) 6.8cm³
  D) 8.3cm³
  Show Answer
  The correct answer is A .
• Question 22: Which of the following reagents will confirm the presence of unsaturation in a compound? Options:
  A) Fehling's solution
  B) Bromine water
  C) Tollen's reagent
  D) Benedict's solution
  Show Answer
  The correct answer is B .
• Question 23:

  C₂H₅ - C = CH₂

  CH₃The correct name of the compound with the above structural formula is

  Options:
  A) 2-methylbut -1-ene
  B) 2-methylbut -2-ene
  C) 2-methylbutane
  D) 2-ethylprop-1 -ene
  E) 2-ethylprop-2-ene
  Show Answer
  The correct answer is A .
• Question 24:

  

  The curve depicts titration between

  Options:
  A) Strong acid and strong base
  B) Strong acid and weak base
  C) Weak acid and weak base
  D) Weak acid and strong base
  Show Answer
  The correct answer is C .
• Question 25:

  

  In the experiment above, a current was passed for 10 minutes and 0.63g of copper was found to be deposited on the cathode of CuSO₄ cells. The weight of silver deposited on the cathode og AgNO³ cell during the same period would be? [Cu = 63, Ag = 108]

  Options:
  A) 0.54g
  B) 1.08g
  C) 1.62g
  D) 2.16g
  E) 3.24g
  Show Answer
  The correct answer is B .
• Question 26: Vulcanization involves the removal of Options:
  A) A monomer
  B) The single bond
  C) The double bond
  D) A polymer
  Show Answer
  The correct answer is C .
• Question 27:

  An unknown organic compound X has a relative molecular mass of 180. It is a colourless crystaline solid, readily soluble in water. X contains the elements C, H and O in the atomic ratio 1: 2:1. The compound has a sweet teste and melts on heating. In the presence of yeast and in the absence of air, X is converted to compound Y and a colourless gas. Compound Y reacts with sodium metal to produce a gas Z which gives a 'pop' sound with a glowing splint. Y also reacts with ethanoic acid to give a sweet smelling compound W.

  The molecular formula of X is

  Options:
  A) C₁₂H₂₂O₁₁
  B) C₆H₁₂O₆
  C) C₃H₆O ₃
  D) C₇H₁₄O₇
  E) C₁₂H₆O₄
  Show Answer
  The correct answer is B .
• Question 28:

  The volume of 2.5 moles of oxygen at s.t.p is

  [Molar volume of a gas at s.t.p = 22.4 dm³]

  Options:
  A) 50.0 dm³
  B) 84.0 dm³
  C) 28.0 dm³
  D) 56.0 dm³
  Show Answer
  The correct answer is D .
• Question 29:

  

  The IUPAC nomenclature of the compound above is

  Options:
  A) 2-ethylpentane
  B) 3,4-dimethylhexane
  C) 2,3-dimethylhexane
  D) 2-ethylhexane
  Show Answer
  The correct answer is B .
• Question 30: A gas exerts pressure on its container because Options:
  A) the molecules of a gas collide with the walls of the container
  B) some of the molecules are moving faster than others
  C) of the collisions of the molecules with each other
  D) of the mass of the molecules of the gas
  Show Answer
  The correct answer is A .