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 301:

  What current in amperes will deposit 2.7g of aluminium in 2 hours?

  [Al = 27, F = 96 500 C mol^-1]

  Options:
  A) 32
  B) 8
  C) 4
  D) 16
  Show Answer
  The correct answer is C .
• Question 302: Which of the following separation processes is most likely to yield high quality ethanol (>95%) from palm wine? Options:
  A) Fractional distillation without a dehydrant
  B) simple distillation with a dehydrant
  C) fractional distillation with a dehydrant
  D) column chromatography
  E) evaporation
  Show Answer
  The correct answer is C .
• Question 303:

  What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

  Options:
  A) 8.0g
  B) 16.0g
  C) 36.0g
  D) 72.0g
  Show Answer
  The correct answer is D .
• Question 304: In the extraction of iron, the waste gas from the furnace is a mixture of Options:
  A) PH₃ CO and CO₂
  B) CO and C
  C) N₂ CO and CO₂
  D) PH₃ and CO
  Show Answer
  The correct answer is A .
• Question 305:

  

  The IUPAC nomenclature of the organic compound with the above structural formula is

  Options:
  A) 3-ethyl-2,5-dimethylhexane
  B) 4-ethyl-2,5-dimethylhexane
  C) 3-ethyl-2,5,5 - trimethylpentane
  D) 3-ethyl, 1,1,4-trimethylpentane
  Show Answer
  The correct answer is A .
• Question 306:

  How many moles of copper would be deposited by passing 3F of electricity through a solution of copper (II) tetraoxosulpohate (IV)?

  (F = 96 500 C mol^-)

  Options:
  A) 0.5
  B) 1.0
  C) 1.5
  D) 3.0
  Show Answer
  The correct answer is C .
• Question 307: In the discovery of protein, the instrument used is Options:
  A) cathode ray tube
  B) glass tube and discharge tube
  C) discharge tube with terminal cathode
  D) discharge tube with central cathode
  Show Answer
  The correct answer is D .
• Question 308: If the relative molecular mass of an element is not a whole number, it can be deduced that the element is Options:
  A) naturally radioactive
  B) abundant in nature
  C) a transition metal
  D) an isotopic mixture
  Show Answer
  The correct answer is D .
• Question 309: Calculate the amount in moles of a gas which occupies 10.5 dm³ at 6 atm and 30^oC [R = 082 atm dm³ K^-1 mol^-1] Options:
  A) 2.536
  B) 1.623
  C) 4.736
  D) 0.394
  Show Answer
  The correct answer is A .
• Question 310: For a general equation of the nature xP + yQ → mR + nS, the expression for the equilibrium constant is Options:
  A) k [P]^x [Q]^y
  B) $\frac{[P{]}^x[Q{]}^y}{[R{]}^m[S{]}^n}$
  C) $\frac{[R{]}^m[S{]}^n}{[P{]}^x[Q{]}^y}$
  D) $\frac{m[R]n[S]}{x[P]y[Q]}$
  Show Answer
  The correct answer is C .