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 1761:

  0.0075 mole of calcium trioxocarbonate (IV) is added to 0.015 mole of a solution of hydrochloric acid. The volume of gas evolved at s.t.p is

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

  Options:
  A) 224cm³
  B) 168cm³
  C) 112cm³
  D) 100cm³
  Show Answer
  The correct answer is B .
• Question 1762: Oxygen-demanding waste are considered to be a water pollutant because they? Options:
  A) deplete oxygen which is necessary for the survival of aquatic organism
  B) increase oxygen which is necessary for survival of aquatic organism
  C) increase other gaseous substances which are necessary for the survival of aquatic organisms
  D) deplete other gaseous species which is necessary for the survival of aquatic organisms
  Show Answer
  The correct answer is A .
• Question 1763:

  Who proposed the planetary model of the atom with electrons orbiting the nucleus?

  Options:
  A) Erwin Schrödinger
  B) Ernest Rutherford
  C) Niels Bohr
  D) J.J. Thomson
  Show Answer
  The correct answer is C .
• Question 1764: A compound contains 40.0% C, 6.7% H 53.3% O. If the molecular mass of the compound is 180, its molecular formula is [C =12, H =1,O] Options:
  A) CH₂O
  B) C₃H₆O₃
  C) C₆H₆O₃
  D) C₆H₁₂O₆
  Show Answer
  The correct answer is D .
• Question 1765:

  Which organic compound is responsible for the characteristic aroma of fruits?

  Options:
  A) Alkane
  B) Alkyne
  C) Ester
  D) Amine
  Show Answer
  The correct answer is C .
• Question 1766: 30cm³ of hydrogen was collected over water at 27°C and 780 mm Hg. If the vapour pressure of water at the temperature of the experiment was 10 mm Hg, calculate the volume of the gas at 760 mm Hg and 7°C? Options:
  A) 40.0 cm³
  B) 35.7 cm³
  C) 28.4 cm³
  D) 25.2 cm³
  Show Answer
  The correct answer is C .
• Question 1767: Nitrogen can best be obtained from a mixture over oxygen and nitrogen by passing the mixture over Options:
  A) potassium hydroxide
  B) heated gold
  C) heated magnesium
  D) heated phosphorus
  E) calcium chloride
  Show Answer
  The correct answer is D .
• Question 1768: Two gas cylinders contain ethylene (ethene) and acetylene respectively. One test which can be used to distinguish between them is by Options:
  A) passing each gas through bromine water
  B) passing each gas through dilute potassium permanganate solution
  C) passing each gas through silver nitrate solution
  D) treating each gas catalytically with excess hydrogen gas
  Show Answer
  The correct answer is C .
• Question 1769: Five compounds R,T,W,X and Y form the following compounds: a basic hydride R.H, an acidic hydride YH, atmospheric oxide W₂O₃, XO₂. which of the elements is an alkali Options:
  A) R
  B) T
  C) W
  D) X
  E) Y
  Show Answer
  The correct answer is A .
• Question 1770: A solid that absorbs water from he atmosphere and forms an aqueous solution is? Options:
  A) hydrophilic
  B) efforescent
  C) deliquescent
  D) hygroscopic
  Show Answer
  The correct answer is C .