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 1011: The greater the different in electronegativity between bonded atoms, the? Options:
  A) lower the polarity of the bond
  B) higher the polarity of the bond
  C) weaker the bond
  D) higher the possibility of the substance formed being a molecule
  Show Answer
  The correct answer is C .
• Question 1012:

  For the reaction NH₄NO₂ $\to$ N₂ + 2H₂O, calculate the volume of nitrogen that would be produced at S. T. P from 320 g of the dioxonitrate(iii)salt. (Relative atomic masses: N = 14, O = 16, H = 1)

  Options:
  A) 2.24 dm ³
  B) 224 dm³
  C) 1.12 dm ³
  D) 112 dm ³
  E) 4.48 dm ³
  Show Answer
  The correct answer is D .
• Question 1013: The density of a certain gas is 1.98gdm^-3 at s.t.p. What is the molecular mas of the gas? Options:
  A) 44.0 g
  B) 54.0 g
  C) 26.0 g
  D) 31.0 g
  Show Answer
  The correct answer is A .
• Question 1014: The oxidation state of chlorine in HClO₄ is Options:
  A) -5
  B) -1
  C) +1
  D) +7
  Show Answer
  The correct answer is D .
• Question 1015: Haematite is an ore of Options:
  A) zinc
  B) lead
  C) iron
  D) copper
  Show Answer
  The correct answer is C .
• Question 1016: A blue solid, T, which weighed 5.0g was placed on a table. After 8 hours, the resulting pink solid was found to weigh 5.5g. It can be inferred that substance T? Options:
  A) is deliquescent
  B) is hydroscopic
  C) has some molecules of water of crystallization
  D) is efflorescent
  Show Answer
  The correct answer is A .
• Question 1017: Starch can be converted to ethyl alcohol by? Options:
  A) distillation
  B) fermentation
  C) isomerization
  D) cracking
  Show Answer
  The correct answer is B .
• Question 1018: An emulsion paint consists of ? Options:
  A) gas or liquid particles dispersed in liguid
  B) liquid particles dispersed in liquid
  C) solid particles dispersed in liquid
  D) solid particles dispersed in solid
  Show Answer
  The correct answer is B .
• Question 1019: Hydrogen diffuses through a porous plug Options:
  A) at the same rate as oxygen
  B) at a slower rate than oxygen
  C) twice as fast as oxygen
  D) three times as fast as oxygen
  E) four times as fast as oxygen
  Show Answer
  The correct answer is E .
• Question 1020:

  

  In the above experiment, the litmus paper will initially

  Options:
  A) be bleached
  B) turn green
  C) turn red
  D) turn blue
  E) turn black
  Show Answer
  The correct answer is D .