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 971: Which one of these compounds will NOT give an oxygen gas on heating? Options:
  A) Manganese dioxide
  B) Hydrogen peroxide
  C) Zinc nitrate
  D) Sodium nitrate
  E) Ammonium nitrate
  Show Answer
  The correct answer is E .
• Question 972:

  Crude petroleum is converted to useful products by the processof?

  Options:
  A) fractional crystallization
  B) fractional distillation
  C) filtration
  D) chromatography
  Show Answer
  The correct answer is B .
• Question 973: Carbon exist naturally in the combined state as Options:
  A) graphite
  B) coal
  C) diamond
  D) wood
  Show Answer
  The correct answer is D .
• Question 974:

  

  In the solubility curve above, water at 98^oC is saturated with KCL and KCIO₃ What is the percentage of KCL impurity in the crystals formed when the solution is cooled to 30 ^oC?

  Options:
  A) 51.5
  B) 45.5
  C) 34.5
  D) 26.5
  Show Answer
  The correct answer is C .
• Question 975:

  

  In the above experiment X is

  Options:
  A) pure nitrogen
  B) a mixture of nitrogen and oxygen
  C) a mixture of nitrogen and carbondioxide
  D) a mixture of oxygen and inert gases
  E) a mixture of nitrogen and inert gases
  Show Answer
  The correct answer is E .
• Question 976:

  

  Use the table above to answer this question. The element that is likely to participate in covalent rather than ionic bonding is

  Options:
  A) Z
  B) Y
  C) X
  D) W
  Show Answer
  The correct answer is C .
• Question 977:

  What is the chemical name for the compound CuCO${}_3$?

  Options:
  A) Copper (iii) carbonate
  B) Copper (ii) carbonate
  C) Copper (i) carbonate
  D) Copper
  Show Answer
  The correct answer is B .
• Question 978:

  

  The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. At room temperature (300 K)

  Options:
  A) Y is twice as soluble as X
  B) X is twice as soluble as Y
  C) X and Y are soluble to the same extent
  D) X is three times as soluble as Y
  E) Y is three times as soluble as X
  Show Answer
  The correct answer is A .
• Question 979: 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) (p)^x (Q)^y / (R)^m (S)ⁿ
  C) (R)^m (S)ⁿ / (p)^x (Q)^y
  D) m(R) n (S) / x(P) y (Q)
  Show Answer
  The correct answer is C .
• Question 980: The octane number of a fuel whose performance is the same as that of a mixture of 55 g of 2,2,4- trimethly pentane and 45 g of n-heptane is ? Options:
  A) 45
  B) 55
  C) 80
  D) 100
  Show Answer
  The correct answer is B .