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 211: The fuming of kettles is caused by the presence in the water of Options:
  A) Calcium tetraoxosulphate (VI)
  B) Calcium hydrogentrioxocarbonate (IV)
  C) Calcium hydroxide
  D) Calcium trioxocarbonate (IV)
  Show Answer
  The correct answer is B .
• Question 212:

  Helium is used in observation of ballons because it is?

  Options:
  A) Light and combustible
  B) light and non-combustible
  C) heavy and combustible
  D) heavy and non-combustible
  Show Answer
  The correct answer is B .
• Question 213: The gas that is the most dangerous pollutant to human is Options:
  A) sulphur (IV) oxide
  B) carbon (IV) oxide
  C) nitrogen (II) oxide
  D) hydrogen sulphide
  Show Answer
  The correct answer is D .
• Question 214: Which of the following will react further with oxygen to form higher oxide? Options:
  A) NO and H₂O
  B) CO and CO₂
  C) SO₂ and NO
  D) CO₂ and H₂O
  Show Answer
  The correct answer is C .
• Question 215:

  Which of the following pairs of substances will react further with oxygen to form a higher oxide?

  Options:
  A) CO${}_2$ and H${}_2$O
  B) NO and H${}_2$O
  C) CO and CO${}_2$
  D) SO${}_2$ and NO
  Show Answer
  The correct answer is D .
• Question 216: According to the kinetic theory an absence in temperature causes the kinetic energy of particles to Options:
  A) decrease
  B) increase
  C) remain constant
  D) be zero
  Show Answer
  The correct answer is D .
• Question 217: When dissolved in water, NaOH flakes show Options:
  A) An endothermic change
  B) An exothermic change
  C) A slow reaction
  D) A rapid reaction
  Show Answer
  The correct answer is B .
• Question 218: The cracking process is very important in the petroleum industry because it. Options:
  A) gives purer products
  B) yields more lubricants
  C) yields more engine fuels
  D) yields more asphalt
  E) yields more candle wax
  Show Answer
  The correct answer is C .
• Question 219:

  

  In the shown experiment (Fig. 1) the litmus paper will initially

  Options:
  A) be bleached
  B) turn green
  C) turn red
  D) turn blue
  Show Answer
  The correct answer is D .
• Question 220: Phenolphthalein in acidic solution is Options:
  A) red
  B) orange
  C) colourless
  D) yellow
  Show Answer
  The correct answer is C .