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 311:

  Which of the following are chemical changes?

  I. cooking of food
  II. digestion of food
  III. freezing of water
  IV. water is heated up

  Options:
  A) I and II
  B) I, II, and III
  C) III and IV
  D) all of the above
  Show Answer
  The correct answer is A .
• Question 312:

  3Cu + pHNO₃ →3Cu(NO)₂ + 4H₂ O + xNO

  In the equation above, the values of p and x respectively are

  Options:
  A) 1 and 3
  B) 2 and 3
  C) 6 and 2
  D) 8 and 2
  Show Answer
  The correct answer is D .
• Question 313:

  What is the IUPAC name for the following compound? HC$\equiv$CCH${}_3$

  Options:
  A) Acetylene
  B) Methyl acetylene
  C) Butanol
  D) Decanoic acid
  Show Answer
  The correct answer is B .
• Question 314: 1.00g of mixture of calcium carbonate and calcium oxide liberated 0.33g of carbon dioxide on strong heating. The percentage of calcium oxide in the mixture is? (Ca = 40, C = 12, O = 16) Options:
  A) 5
  B) 15
  C) 25
  D) 35
  E) 50
  Show Answer
  The correct answer is C .
• Question 315: There are basic particles from which matter called be made except Options:
  A) Salt
  B) Atom
  C) Ion
  D) Molecule
  Show Answer
  The correct answer is A .
• Question 316: The oxidation number of manganese in KMnO₄ is? Options:
  A) +1
  B) +3
  C) +5
  D) +7
  E) +2
  Show Answer
  The correct answer is D .
• Question 317: The reaction 3C(s) + 2Fe₂O₃(s) = 4Fe(s) + 3CO₂(g): $\mathrm{\Delta }$H =46.0 kJ is Options:
  A) isothermic
  B) adiabatic
  C) isobaric
  D) endothermic
  E) exothermic
  Show Answer
  The correct answer is D .
• Question 318: In what respect will two dry samples of nitrogen gas differ from each other if sample 1 is prepared by completely removing CO₂ and O₂ from air, and sample 2 is prepared by passing purified nitrogen(i)oxide over heated copper? sample 1 is Options:
  A) purer than sample 2
  B) slightly denser than sample 2
  C) in all respects the same as sample 2
  D) colourless but sample 2 has a light brown colour
  E) slightly less reactive than sample 2
  Show Answer
  The correct answer is B .
• Question 319:

  

  Choose the correct option from the graph above.

  3Fe_(S) + 4H₂O_(g) ⇌ Fe₃O_4(s) + 4H_2(g). The equilibrium constant, K, of the reaction above is represented as

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is C .
• Question 320:

  The IUPAC name for CH${}_3$CH${}_2$COOCH${}_2$CH${}_3$ is

  Options:
  A) methylpropanoate
  B) ethylethanoate
  C) ethylpropanoate
  D) methylethanoate
  Show Answer
  The correct answer is C .