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 1661: How many moles of oxygen molecules would be produced from the decomposition of 2.50 moles of potassium trioxochlorate (V)? Options:
  A) 2.50
  B) 3.50
  C) 3.75
  D) 7.50
  Show Answer
  The correct answer is C .
• Question 1662:

  The shapes of water, ammonia, carbon (iv) oxide and methane are respectively

  Options:
  A) linear, tetrahedral, angular and pyramidal
  B) angular, pyramidal, linear and tetrahedral
  C) pyramidal, linear, tetrahedral and angular
  D) tetrahedral, angular, pyramidal and linear
  Show Answer
  The correct answer is B .
• Question 1663: An organic compound containing 40.1% carbon and 6.6% hydrogen has an empirical formula of? Options:
  A) C₂H₄O₂
  B) C₂H₃O₂
  C) CH₂O
  D) CH₃O
  Show Answer
  The correct answer is C .
• Question 1664:

  

  The compound above is

  Options:
  A) glycol
  B) primary alkanol
  C) secondary alkanol
  D) tertiary alkanol
  Show Answer
  The correct answer is C .
• Question 1665: An example of a hygroscopic substance is Options:
  A) CuO _(S).
  B) MgCL_2(S).
  C) CaCL_2(S).
  D) NaOH_(S).
  Show Answer
  The correct answer is A .
• Question 1666: If the silver mirror test is positive, it indicates the presence of an Options:
  A) alkyne
  B) alkanol
  C) alkanone
  D) alkanal
  Show Answer
  The correct answer is D .
• Question 1667: Which are the correct IUPAC names for H-CO₂CH₃ and CH = CH Options:
  A) Methyl methanoate and ethene
  B) Metanoic acid and ethyne
  C) Ethyl methanoate and ethyne
  D) Methyl methanoate and ethyne
  E) Ethanoic acid and ethene
  Show Answer
  The correct answer is A .
• Question 1668: On heating, under suitable conditions, 1 litres of monoatomic gas,X, combines with 1¹/₂ litres of an oxide, What is the formula of the oxide. Options:
  A) XO₃
  B) X₂O₃
  C) X₃O₂
  D) XO₂
  E) None of the above
  Show Answer
  The correct answer is B .
• Question 1669: A sample of orange juice is found to have a pH of 3.80. What is he concentration of the hydroxide ion in the juice? Options:
  A) 1.6 x 10^-4
  B) 6.3 x 10^-11
  C) 6.3 x 10^-4
  D) 1.6 x 10^-11
  Show Answer
  The correct answer is B .
• Question 1670:

  Which of these sources of water may likely contain the least concentration of Ca${}^{2+}$ and Mg${}^{2+}$?

  Options:
  A) Spring water
  B) River water
  C) Tap water
  D) Sea water
  Show Answer
  The correct answer is C .