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 1791: Which ONE of the following statements is true? Options:
  A) All alkali metals salts dissolves with dissociation in water
  B) Most ionic substances are easily vaporized
  C) Ionic substances exist only as liquid
  D) Non-ionic substances are good electrolytes
  E) Nitrogen exists in a trivalent state in ammonium salts
  Show Answer
  The correct answer is A .
• Question 1792: Which of the following is arranged in order of increasing electronegativity? Options:
  A) Chlorine, aluminium, magnesium, phosphorus, sodium
  B) sodium, magnesium, aluminium, phosphorus, chlorine
  C) Chlorine, phosphorus, phosphorous, aluminium, magnesium, sodium
  D) Sodium, chlorine, phosphorus, magnesium, aluminium
  Show Answer
  The correct answer is B .
• Question 1793: On heating, under suitable conditions, 1 litres of monoatomic gas,X, combines with 1¹/₂ litres of an oxide, What is the formula of the oxide. Options:
  A) XO₃
  B) X₂O₃
  C) X₃O₂
  D) XO₂
  E) None of the above
  Show Answer
  The correct answer is B .
• Question 1794: Which of the following statements is correct during the electrolysis of a caustic soda solution using platinum electrodes? Options:
  A) Oxygen gas is given off at the cathode
  B) Hydrogen gas is given of at the anode
  C) Sodium metals is deposited at the anode
  D) Sodium metal is deposited at the cathode
  E) AAlkalinity at the cathode increases
  Show Answer
  The correct answer is E .
• Question 1795:

  200cm${}^3$ of 0.50mol/dm${}^3$ solution of calcium hydrogen trioxocarbonate (IV) is heated. The maximum weight of solid precipitated is

  Options:
  A) 10g
  B) 25g
  C) 20g
  D) 15g
  Show Answer
  The correct answer is A .
• Question 1796: The process of converting starch to ethanol is Options:
  A) cracking
  B) distillation
  C) fermentation
  D) oxidation
  Show Answer
  The correct answer is C .
• Question 1797: Which of the following is NOT correct test for the named organic compound in each case? Options:
  A) Butanoic acid solution gives effervescence with Na₂CO₃ solution
  B) Glucose when reacted with Na₂CrO₄ at 0°C will show immediate discharge of colour
  C) When but-2-ene is reacted with dilute solution of KMnO₄ the purple colour of KMnO is discharged readily even room temperature
  D) When butan-2-ol is boiled with butanoic acid with a drop of concentrated H₂SO₄ a sweet smelling liquid is produced
  Show Answer
  The correct answer is B .
• Question 1798: 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 1799: The relative atomic mass of a naturally occurring lithium consisting of 90%$\frac{7}{3}$Li and 10%$\frac{6}{3}$Li is Options:
  A) 6.2
  B) 6.8
  C) 7.1
  D) 6.9
  Show Answer
  The correct answer is D .
• Question 1800:

  Alkanol + Alkanoic ↔ Ester + Water

  The reverse reaction above is known as

  Options:
  A) Hydrolysis
  B) Saponification
  C) Hydration
  D) Fermentation
  Show Answer
  The correct answer is A .