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 1971:

  

  Use the above options to the question. The products formed on hydrolysis of

  Options:
  A) A
  B) B
  C) C
  D) D
  E) E
  Show Answer
  The correct answer is C .
• Question 1972:

  

  Figure 1 above shows part of the periodic Table which of the elements belongs to the p-block?

  Options:
  A) S, T and U
  B) V, W and X
  C) S and T only
  D) P, Q and R
  E) V, W, X and S
  Show Answer
  The correct answer is D .
• Question 1973: What is the volume of energy required to burn 45cm3 of mixture at S.T.P Options:
  A) 135.0cm³
  B) 150.0cm³
  C) 45.0cm³
  D) 90.0cm³
  Show Answer
  The correct answer is D .
• Question 1974: Sieving is a technique used to separate mixture containing solid particles of Options:
  A) small sizes
  B) large sizes
  C) differents sizes
  D) the same sizes
  Show Answer
  The correct answer is C .
• Question 1975: The distance between the nuclei of chlorine atoms in a chlorine molecule is 0.194nm. The atomic radius of chlorine atom is Options:
  A) 0.097nm
  B) 0.914nm
  C) 0.388nm
  D) 2.388nm
  Show Answer
  The correct answer is A .
• Question 1976:

  Mg_(s) + 2HCl_(aq) → MgCl_2(aq) + H_2(g)

  From the equation above, the mass of magnesium required to react with 250cm³ of 0.5M HCl is

  [Mg = 24]

  Options:
  A) 0.3g
  B) 1.5g
  C) 2.4g
  D) 3.0g
  Show Answer
  The correct answer is B .
• Question 1977: Which of the following is a property of ionic chlorides? Options:
  A) They can be decomposed by heat
  B) They react with aqueous AgNO₃ to give a white precipiate which is soluble in excess ammonia
  C) They explode when in contact with dry ammonia
  D) They react with concentrated tetraoxosulphate (IV) acid to give white fumes of chlorine gas
  Show Answer
  The correct answer is B .
• Question 1978: A mixture contains 20cm³ of hydrogen, 35cm³ of oxygen, 15cm³ of carbon monoxide and 10cm³ of nitrogen at S.T.P. Which of the following gives the mole fraction of hydrogen in this mixture? Options:
  A) 0.02
  B) 0.16
  C) 0.20
  D) 0.25
  E) 20
  Show Answer
  The correct answer is D .
• Question 1979:

  H₃PO_4(aq) + H₂O_(l) ↔ H₂PO₄^-_(aq) + H₃O⁺_(aq)

  ΔH = -13kJ at 298K

  In the reaction above, an increase in temperature would

  Options:
  A) slow downthe reverse reaction
  B) have no effect on the reaction
  C) favour the reverse reaction
  D) favour the forward reaction
  Show Answer
  The correct answer is C .
• Question 1980: Pure solvents are obtained by Options:
  A) distillation
  B) condensation
  C) extraction
  D) evaporation
  E) desolution
  Show Answer
  The correct answer is A .