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 811: 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 812:

  The Sulphide which is insoluble in dilute hydrochloric acid is

  Options:
  A) FeS
  B) CuS
  C) ZnS
  D) Na2S
  Show Answer
  The correct answer is B .
• Question 813:

  Sodium reacts vigorously with water to produce

  Options:
  A) Sodium chloride (NaCl) and oxygen gas (O2)
  B) Sodium nitrate (NaNO3) and water (H2O)
  C) Sodium hydroxide (NaOH) and hydrogen gas (H2)
  D) Sodium oxide (Na2O) and hydrogen gas (H2)
  Show Answer
  The correct answer is C .
• Question 814:

  What volume of 0.100M sodium trioxonitrate (V) solution contains 5g of solute.

  [Na = 23, N = 14, O = 16]

  Options:
  A) 1.7 litres
  B) 0.420 litres
  C) 0.588 litres
  D) 2.35 litres
  Show Answer
  The correct answer is C .
• Question 815:

  Which of the following substances is NOT hygroscopic?

  Options:
  A) Salt
  B) Sugar
  C) Silica gel
  D) Aluminum
  Show Answer
  The correct answer is D .
• Question 816: An increase in the pressure exerted on gas at a constant temperature results in Options:
  A) a decrease in the number of effective collisions
  B) a decrease in volume
  C) an increase in the average intermolecular distance
  D) an increase in volume
  Show Answer
  The correct answer is B .
• Question 817:

  The sulphide that is commonly used in coating electric fluorescent tubes is?

  Options:
  A) iron(ii)Sulphide
  B) tin(ii)sulphide
  C) Zinc Sulphide
  D) lead(iv) Sulphide
  Show Answer
  The correct answer is C .
• Question 818:

  200cm³ each of 0.1M solutions of lead (II) trioxonitrate (V) and hydrochloric acid were mixed. Assuming that lead (II) chloride is completely insoluble, calculate the mass of lead (II) chloride that will be precipitated.

  [Pb = 207, Cl= 35.5, N = 14, O = 16]

  Options:
  A) 2.78g
  B) 5.56g
  C) 8.34g
  D) 11.12g
  Show Answer
  The correct answer is B .
• Question 819:

  

  Use the graph above to answer this question.If the gas is cooled, at what temperature will it start to condense?

  Options:
  A) 125 ^oC
  B) 150^oC
  C) 175^oC
  D) 250^oC
  Show Answer
  The correct answer is B .
• Question 820: Detergents are manufacture with strength hydrocarbon chains is to make them Options:
  A) soluble
  B) biodegradable
  C) cheaper
  D) foamy
  Show Answer
  The correct answer is B .