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 141:

  

  Which of the compounds above would react to take up two molecules of bromine during bromination?

  Options:
  A) l only
  B) lll only
  C) l and ll only
  D) ll and lll only
  Show Answer
  The correct answer is C .
• Question 142: Which of the following statements applies during the electroysis of sodium hydroxide sodium hydroxide solution using platinum electrodes? Options:
  A) Na⁺ ions are discharged at the cathode
  B) Hydrogen ions are discharged at the anode
  C) the concentration of sodium hydroxide decrease at both electrode compartments
  D) the concentration of sodium hydroxide increases at the cathode only
  E) the concentration of sodium hydroxide increases at the anode only
  Show Answer
  The correct answer is D .
• Question 143: The characteristics reaction of carbonyl compounds is? Options:
  A) substitution
  B) elimination
  C) addition
  D) saponfication
  Show Answer
  The correct answer is C .
• Question 144: Calcium hydroxide and ammonium chloride when heated together will give an important product. This compound may be obtained dry by Options:
  A) dissolving it in water, recrystallizing it and then drying in the oven
  B) passing it through a concentrated aqueous solution of sodium hydroxide
  C) passing it through calcium oxide
  D) passing it through concentrated sulphuric acid
  E) passing it through anhydrous calcium choride
  Show Answer
  The correct answer is C .
• Question 145: At 25^oC and 1atm, a gas occupies a volume of 1.50dm³. What volume will it occupy at 100^oC and 1atm? Options:
  A) 1.88 dm³
  B) 6.00 dm³
  C) 18.80 dm³
  D) 18.80 dm³
  E) 60.00dm³
  Show Answer
  The correct answer is A .
• Question 146: The drying agent suitable for drying ammonia is Options:
  A) Calcium Chloride
  B) Calcium Oxide
  C) Phosphorus(V) Oxide
  D) Concentrated H₂SO₄
  Show Answer
  The correct answer is B .
• Question 147:

  Alkanes are used mainly?

  Options:
  A) in the textile industry
  B) in the hydrogenation of oils
  C) as domestic and industrial fuels
  D) as fine chemicals
  Show Answer
  The correct answer is C .
• Question 148: If chlorine is bubbled into water and the resulting yellowish-green solution is exposed to bright sunlight for a while, the solution will decompose giving out Options:
  A) oxygen and leaving behind aqueous hydrochloric acid
  B) chlorine and oxygen
  C) oxygen, hydrogen and chlorine
  D) oxygen, thereby producing hypochlorous acid
  Show Answer
  The correct answer is A .
• Question 149:

  Which two gases can be used for the demonstration of the fountain experiment?

  Options:
  A) SO${}_3$ and NH${}_3$
  B) SO${}_2$ and NH${}_3$
  C) HCl and NH${}_3$
  D) SO${}_2$ and HCl
  Show Answer
  The correct answer is C .
• Question 150:

  

  In the diagram above, the gas produced is

  Options:
  A) NO
  B) NO₂
  C) N₂O
  D) N₂O₄
  Show Answer
  The correct answer is A .