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 251:

  Which of the following is a common laboratory indicator for bases?

  Options:
  A) Methyl orange
  B) Phenolphthalein
  C) Bromothymol blue
  D) Litmus
  Show Answer
  The correct answer is B .
• Question 252: Which of these properties gives a solid its definite shape? Options:
  A) strong intermolecular attraction
  B) high melting point
  C) high boiling point
  D) weak intermolecular attraction
  Show Answer
  The correct answer is A .
• Question 253: Which of the following processes NOT lead to a chemical change? Options:
  A) Strirring iron in sulphur (IV) acid
  B) Stirring sodium carbonate in water
  C) Stirring glucose in concentrated sulphur (IV) acid
  D) Mixing sulphur (IV) acid with potassium carbonate
  E) Titrating an acid against base
  Show Answer
  The correct answer is B .
• Question 254:

  The nucleusof a hydrogen atom consist of a?

  Options:
  A) 1 proton only
  B) 1 proton, 2 neutron
  C) 1 neutron only
  D) 1 electron only
  Show Answer
  The correct answer is A .
• Question 255: Which of the following will have its mass increased when heated in air? Options:
  A) Helium
  B) Magnesium
  C) Copper pyrites
  D) Glass
  Show Answer
  The correct answer is B .
• Question 256:

  The size (diameter) of five elements are in the order R < T < W < X < Y, Y being the largest. If each atom has an electron situated on its circumference, and neglecting other factors, which of the atoms will lose its electron most reluctantly?

  Options:
  A) R
  B) T
  C) W
  D) X
  E) Y
  Show Answer
  The correct answer is A .
• Question 257: The oxidation of ammonia in excess air produces Options:
  A) NO
  B) N₂O
  C) NO₂
  D) N₂O₄
  Show Answer
  The correct answer is A .
• Question 258: A white solid suspected to be lead trioxonitrate (V) zinc trioxocarbonate (IV) or calcium trioxocabonate (IV) was heated strongly. Its residue which was yellow when hot and white when cold is? Options:
  A) lead (II) oxide
  B) calcium oxide
  C) zinc oxide
  D) lead nitrate
  Show Answer
  The correct answer is C .
• Question 259: Which of the following represents ethyl ethanonate? Options:
  A) CH₃CH₂CO₂CH₃
  B) (CH₃CO₂)₂O
  C) CH₃CH₂CO₂CH₂CH₃
  D) CH₃CO₂CH₂CH₃
  E) CH₃CH₂COCH₂CH₃
  Show Answer
  The correct answer is D .
• Question 260: In the reaction Fe + Cu²⁺ $\to$ Fe²⁺ + Cu,iron displaces copper ions to from copper. This is due to the fact that Options:
  A) irn is in the metallic from while the copper is in the ionic from
  B) the atomic weight of copper is greater than that of iron
  C) copper is greater than iron
  D) copper metal has more electrons than iron metal
  E) iron is higher in the electrochemical series than copper
  Show Answer
  The correct answer is E .