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 1191: Aromatic and aliphatic hydrocarbons can be distinguished from each other by the? Options:
  A) action of bromine
  B) use of polymerization reaction
  C) action of heat
  D) use of oxidation reaction
  Show Answer
  The correct answer is C .
• Question 1192: Which of the following is physical change? Options:
  A) Burning kerosene
  B) Freezing ice cream
  C) Exposing white phosphorus
  D) Dissolving calcium in water
  Show Answer
  The correct answer is B .
• Question 1193:

  A chemical widely used as a fertilizer is?

  Options:
  A) galena
  B) bauxite
  C) emerald
  D) nitrochalk
  Show Answer
  The correct answer is D .
• Question 1194: An element X forms the following compounds with chlorine; XCl₄, XCl₃, XCl₂. This illustrates the Options:
  A) law of multiple proportions
  B) law of chemical proportions
  C) law of simple proportions
  D) law of conservation of mass
  E) law of definite proportions
  Show Answer
  The correct answer is A .
• Question 1195: The tincture of iodine means iodine dissolved in Options:
  A) ethanol
  B) bromine chloride
  C) chlorine water
  D) water
  Show Answer
  The correct answer is A .
• Question 1196: Which is the temperature of a given mass of a gas initially at 0°C and 9 atm, if the pressure is reduced to 3 atm at constant volume? Options:
  A) 91K
  B) 182K
  C) 273K
  D) 819K
  Show Answer
  The correct answer is A .
• Question 1197:

  

  The diagram above represents an atom that can combine with chlorine to form

  Options:
  A) a covalent bond
  B) an electrovalent bond
  C) a hydrogen bond
  D) a co-ordinate bond
  Show Answer
  The correct answer is B .
• Question 1198: On cracking medicinal paraffin, a gas is evolved which gives a pop sound with a lighted splinter and an oily liquid which decolourizes bromine solution is also obtained. The products of the cracking are ? Options:
  A) carbon (IV) oxide and alkyne
  B) carbon (ll) oxide and alkene
  C) hydrogen gas and alkene
  D) hydrogen gas and alkane
  Show Answer
  The correct answer is C .
• Question 1199: Tetraoxosulphate (IV) ions are finally tested using? Options:
  A) acidified silver nitrate
  B) acidified barium chloride
  C) ime-water
  D) dilute hydrochloric acid
  E) acidified lead nitrate
  Show Answer
  The correct answer is B .
• Question 1200: When copper (ii) sulphate solution is treated with excess ammonium hydroxide, a precipitate is first formed, and then this dissolves to give a deep blue solution. This deep blue solution is a Options:
  A) Cu(OH)₂
  B) CuSo₄.5H₂O
  C) (NH₄)₂SO₄
  D) Cu(NH₃)₄(OH)₂
  E) CuSO₄.(NH₄)₂SO₄.2H₂O
  Show Answer
  The correct answer is E .