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 881: Which of the following gases contains the least number of atoms at s.t.p? Options:
  A) 1 mole of butane
  B) 3 mole of ozone
  C) 4 mole of chlorine
  D) 7 mole of argon
  Show Answer
  The correct answer is A .
• Question 882:

  An isotope has an atomic number of 15 and a mass number of 31. The number of protons it contains is

  Options:
  A) 16
  B) 15
  C) 46
  D) 31
  Show Answer
  The correct answer is B .
• Question 883:

  A secondary alkanol can be oxidized to give an

  Options:
  A) alkanone
  B) alkyne
  C) alkanoic acid
  D) alkanal
  Show Answer
  The correct answer is A .
• Question 884:

  A correct electrochemical series can be obtained from Na, Ca, Al, Mg, Zn, Fe, Pb, H, Cu, Hg, Ag, Au by interchanging

  Options:
  A) Al and Mg
  B) Zn and Fe
  C) Zn and Pb
  D) Pb and H
  Show Answer
  The correct answer is A .
• Question 885: Water for town supply is chlorinate to make it free from Options:
  A) bad colour
  B) bacteria
  C) temporary hardness
  D) permanent hardness
  Show Answer
  The correct answer is B .
• Question 886: How many protons, neutrons and electrons respectively are present in the element 60/27 Co? Options:
  A) 27, 33 and 33
  B) 33, 27 and 27
  C) 27, 33, and 27
  D) 60, 33 and 60
  Show Answer
  The correct answer is C .
• Question 887: Brass is an alloy containing copper and? Options:
  A) zinc
  B) tin
  C) aluminium
  D) silver
  E) lead
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  The correct answer is A .
• Question 888:

  

  The diagram above best illustrates the effect of decrease in

  Options:
  A) concentration
  B) temperature
  C) surface area
  D) pressure
  Show Answer
  The correct answer is A .
• Question 889: Potassium vapour burns with a Options:
  A) blue flame
  B) brick-red flame
  C) violet flame
  D) golden-yellow flame
  Show Answer
  The correct answer is C .
• Question 890: If a current of 1.5 A is passed for 4.00 hours through a molten tin salt and 13.3g of tin is deposited, what is the oxidation state of the metal in the salt?(Sn = 118.7, F = 96500 C mol^-1) Options:
  A) 1
  B) 2
  C) 3
  D) 4
  Show Answer
  The correct answer is B .