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 131: Which of the following metals will displace iron from a solution of iron(ll)tetraoxosulphate(lV)? Options:
  A) Copper
  B) Mercury
  C) Silver
  D) Zinc
  E) Gold
  Show Answer
  The correct answer is D .
• Question 132: When chlorine Is passed into water and the resulting solution exposed to sunlight, the product formed are Options:
  A) Chlorine gas and hydrogen
  B) Oxygen and oxochlorate (I) acid
  C) Chlorine gas and oxochlorate (I) acid
  D) Hydrochloric acid and oxygen
  Show Answer
  The correct answer is D .
• Question 133: Which of the following ions require the largest quantity of electricity for discharge at an electrode? Options:
  A) 4.0 moles of Cl^-
  B) 3.0 moles of Na⁺
  C) 2.5 moles of Cu²⁺
  D) 2.0 moles of Al³⁺
  Show Answer
  The correct answer is C .
• Question 134: Which of the following is a solvent for perfumes? Options:
  A) C₅H₁₂
  B) C₄H₆
  C) CH₃COOH
  D) C₂H₅OH
  Show Answer
  The correct answer is D .
• Question 135: Calculate the amount in moles of a gas which occupies 10.5 dm³ at 6 atm and 30^oC [R = 082 atm dm³ K^-1 mol^-1] Options:
  A) 2.536
  B) 1.623
  C) 4.736
  D) 0.394
  Show Answer
  The correct answer is A .
• Question 136: A major source of oxide of oxygen is from the burning of Options:
  A) coal
  B) wood
  C) fuel
  D) chlorofluorocarbons
  Show Answer
  The correct answer is A .
• Question 137: 28.8 cm³ of nitrogen at 15°C is cooled to O°C at constant pressure, the new volume of nitrogen is? Options:
  A) 17.4 cm³
  B) 14.7 cm³
  C) 27.3 cm³
  D) 31.7 cm³
  Show Answer
  The correct answer is C .
• Question 138: The oxidation number of iodine in KIO₃ is Options:
  A) +7
  B) +3
  C) +5
  D) +6
  Show Answer
  The correct answer is C .
• Question 139: The number of electronic shells contained in an atom with electron configuration 1s²2s²2p⁶3s²3p⁶4s² is Options:
  A) 3
  B) 2
  C) 4
  D) 5
  Show Answer
  The correct answer is C .
• Question 140: In the reaction E+F ↔ G+H, the backward reaction is favoured if the concentration of Options:
  A) F is increased
  B) E is increased
  C) E is reduced
  D) G is reduced
  Show Answer
  The correct answer is C .