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 71:

  The heat of reaction can be determined experimentally using a device called a

  Options:
  A) Calorimeter
  B) Barometer
  C) Spectrometer
  D) Thermometer
  Show Answer
  The correct answer is A .
• Question 72: The conversion of open chain alkanes into cycloalkanes and aromatic compounds is called Options:
  A) cracking
  B) reforming
  C) isomerization
  D) polymerization
  Show Answer
  The correct answer is B .
• Question 73: The final products of the reaction between methane and chlorine in the presence of ultraviolet light are hydrogen chloride and Options:
  A) tricloromethane
  B) dichloromethane
  C) tetrachloromethane
  D) chloromethane
  Show Answer
  The correct answer is C .
• Question 74: Which of the following oxides of nitrogen is unstable in air? Options:
  A) NO₂
  B) NO
  C) N₂O₄
  D) N₂O_5-
  Show Answer
  The correct answer is B .
• Question 75:

  To what temperature must a gas at 273k be heated in order to double both its volume and pressure?

  Options:
  A) 298K
  B) 546K
  C) 819K
  D) 1092K
  Show Answer
  The correct answer is D .
• Question 76: 5 block elements of the periodic table one made up of Options:
  A) groups 1, 2, 3
  B) groups 1, and 2
  C) group 3
  D) group 3 to 7
  Show Answer
  The correct answer is B .
• Question 77:

  Which one of the following is not a mixture?

  Options:
  A) Air
  B) Mercury
  C) Milk
  D) Cement
  Show Answer
  The correct answer is B .
• Question 78:

  If 10.5g of lead (II) trioxonitrate (V) is dissolved in 20cm³ of distilled water at 18^oC, the solubility of the solute in mol dm^-3 is

  [Pb = 207, N = 14, O = 16]

  Options:
  A) 1.60
  B) 5.25
  C) 16.00
  D) 525.00
  Show Answer
  The correct answer is A .
• Question 79:

  

  Use the graph above to answer this question.

  A sample, X, solid at room temperature, was melted, heated to a temperature of 358 K and allowed to cool as shown in OPQR. The section OP suggests that X is in the

  Options:
  A) liquid sate
  B) solid/liquid state
  C) solid state
  D) gaseous state
  Show Answer
  The correct answer is A .
• Question 80:

  The reactions involving simultaneous oxidation and reduction?

  Options:
  A) Automatic reactions
  B) Alternate reactions
  C) Reduction agency
  D) Redox reactions
  Show Answer
  The correct answer is D .