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 2091: A side effect of soft water is that Options:
  A) it gives offensive taste
  B) excess calcium is precipitated
  C) it attcaks lead contained in pipes
  D) it encourages the growth of bacteria
  Show Answer
  The correct answer is C .
• Question 2092: When plastics and packaging materials made from chloroethene are burnt in the open, the mixture of gases released into the atmosphere is most likely to contain? Options:
  A) ethane
  B) chlorine
  C) hydrogen chloride
  D) ethene
  Show Answer
  The correct answer is C .
• Question 2093:

  What is the mass percentage of carbon (C) in methane (CH4)? (The molar mass of carbon is approximately 12 g/mol.)

  Options:
  A) 25%
  B) 12%
  C) 75%
  D) 50%
  Show Answer
  The correct answer is C .
• Question 2094: The main impurity in iron ore during the extraction of iron is Options:
  A) Silicon (IV) oxide
  B) Carbon (IV) oxide
  C) Calcium trioxosilicate
  D) Sulphur (II) oxide
  Show Answer
  The correct answer is A .
• Question 2095: Which of the following methods can be used to obtain pure water from a mixture of sand, water and methanoic acid? Options:
  A) netralization with NaOHfoolowed by filtration
  B) neutralization with NaOH followed by distillation
  C) fractional distillation
  D) filtration followed by distillation
  Show Answer
  The correct answer is D .
• Question 2096:

  NaCI_(s) + H₂SO_4(I) → HCI_(g) + NaHSO_4(s).

  In the reaction above, H₂SO₄ behaves as?

  Options:
  A) a strong acid
  B) an oxidizing agent
  C) a good solvent
  D) a dehydrating agent
  Show Answer
  The correct answer is A .
• Question 2097: If a gas occupies a container of volume 146 cm³ at 18°C and 0.97`atm, its volume 146cm³ at s.t.p is? Options:
  A) 133
  B) 146
  C) 266
  D) 292
  Show Answer
  The correct answer is A .
• Question 2098:

  A sample of a substance containing only C and H burns in excess O₂ to yield 4.4g of CO₂

  And 2.7 g of H₂O. The empirical formula of a substance is?(C = 12, O = 16, H = 1)

  Options:
  A) CH₃
  B) CH₂
  C) CH₄
  D) C₂H₂₄
  Show Answer
  The correct answer is A .
• Question 2099: Given the reactions (i) Fe_(s) + X(NO₃)_2(aq) → Fe(NO₃) + X_(s) (ii) H_2(g) + XO _{→ X + H2}O_(s); X is likely to be?
  Options:
  A) copper
  B) zinc
  C) calcium
  D) lead
  Show Answer
  The correct answer is A .
• Question 2100:

  

  The major product of the dehydration of the compound above is

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