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 2051:

  A solution X, on mixing with AgNO${}_3$ solution gives a white precipitate soluble in aqueous NH${}_3$, a solution Y, when also added to X, also gives a white precipitate which is soluble when heated solutions X and Y respectively contain

  Options:
  A) Al${}^{3+}$, Cl${}^{-}$
  B) Hg${}^{+}$, SO${}_4^{2-}$
  C) Pb${}^{2+}$, Cl${}^{-}$
  D) Ag${}^{+}$, SO${}_4^{2-}$
  Show Answer
  The correct answer is C .
• Question 2052:

  How many alkoxyalkanes can be obtained from the molecular formula C${}_4$H${}_{10}$O?

  Options:
  A) 4
  B) 2
  C) 1
  D) 3
  Show Answer
  The correct answer is D .
• Question 2053: Ammonium chloride can be separated from its mixture with common salt by Options:
  A) Distillation
  B) Evaporation
  C) Decantation
  D) Sublimation
  Show Answer
  The correct answer is D .
• Question 2054:

  How many moles of limestone will be required to produce 5.6g of CaO?

  [Ca = 40, C = 12, O= 16]

  Options:
  A) 0.20 mol
  B) 0.10 mol
  C) 1.12 mol
  D) 0.56 mol
  Show Answer
  The correct answer is B .
• Question 2055:

  

  The above graph shows a typical heating curve from the solid phase through the liquid phase to the gaseous phase of a substance. Which part of the curve shows solid and liquid in equilibrium?

  Options:
  A) T
  B) U
  C) X
  D) Y
  Show Answer
  The correct answer is A .
• Question 2056:

  Which of the following is a characteristic property of acids?

  Options:
  A) Turn litmus paper blue
  B) Bitter taste
  C) pH value above 7
  D) React with metals to produce hydrogen gas
  Show Answer
  The correct answer is D .
• Question 2057:

  If acidified Potassium Dichromate(VI) (K${}_2$Cr${}_2$O${}_7$) acts as oxidizing agent, color changes from

  Options:
  A) yellow to green
  B) orange to green
  C) yellow to red
  D) orange to red
  Show Answer
  The correct answer is B .
• Question 2058:

  What process would coal undergo to give coal gas, coal tar, ammoniacal liquor and coke?

  Options:
  A) Steam distillation
  B) Destructive distillation
  C) Liquefication
  D) Hydrolysis
  Show Answer
  The correct answer is B .
• Question 2059:

  

  Use the following option above to answer this question. Which of the following compounds in solution will turn red litmus paper blue?

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is C .
• Question 2060:

  Which of the following methods can be used to remove temporary hardness from water?

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