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 1191:

  200cm${}^3$ of 0.50mol/dm${}^3$ solution of calcium hydrogen trioxocarbonate (IV) is heated. The maximum weight of solid precipitated is

  Options:
  A) 10g
  B) 25g
  C) 20g
  D) 15g
  Show Answer
  The correct answer is A .
• Question 1192:

  Given that M is the mass of a substance deposited during electrolysis and Q is the quantity of electricity consumed, then Faraday's first law can be written as

  [Electrochemical equivalent]

  Options:
  A) M = E/Q
  B) M = EQ
  C) M = Q/E
  D) M = E/2Q
  Show Answer
  The correct answer is B .
• Question 1193:

  The emission of two successive beta particles from the nucleus ${}_{15}^{32}P$ will produce

  Options:
  A) ${}_{14}^{30}$Si
  B) ${}_{13}^{32}$Al
  C) ${}_{17}^{32}$Cl
  D) ${}_{16}^{32}$S
  Show Answer
  The correct answer is C .
• Question 1194:

  The maximum electron in N shell is?

  Options:
  A) 2
  B) 8
  C) 18
  D) 32
  Show Answer
  The correct answer is D .
• Question 1195:

  If gas A has a molar mass of 32 g/mol and gas B has a molar mass of 64 g/mol, what is the ratio of their diffusion rates?

  Options:
  A) 2:1
  B) 1:2
  C) 1:1
  D) 1:4
  Show Answer
  The correct answer is A .
• Question 1196: Sodium hydroxide solution can be conveniently stored in a container made of? Options:
  A) lead
  B) zinc
  C) aluminium
  D) copper
  Show Answer
  The correct answer is D .
• Question 1197:

  An organic compound has an empirical formula CH₂O and vapour density of 45.

  What is the molecular formula?

  [C = 12, H = 1, O = 16]

  Options:
  A) C₃H₇OH
  B) C₂H₅OH
  C) C₃H₆O₃
  D) C₂H₄O₂
  Show Answer
  The correct answer is C .
• Question 1198: 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 1199: What is the decrease in volume of air when pyrogallol is shaken with 30.00cm³ of air ? Options:
  A) 15.00cm³
  B) 6.30cm³
  C) 0.63cm³
  D) 0.06cm³
  Show Answer
  The correct answer is B .
• Question 1200:

  Which of the following methods is commonly used to remove suspended impurities from water?

  Options:
  A) Fluoridation
  B) Chlorination
  C) Filtration
  D) Distillation
  Show Answer
  The correct answer is C .