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 1271: The radioactive emission with the least ionization power is Options:
  A) $\alpha -particles$
  B) X-rays
  C) $\gamma -rays$
  D) $\beta -rays$
  Show Answer
  The correct answer is C .
• Question 1272: Mortar is NOT used for under-water construction because Options:
  A) it hardens by lose of water
  B) its hardening doe not depend upon evaporation
  C) it requires concrete to harden
  D) it will be washed away by the flow of water
  Show Answer
  The correct answer is A .
• Question 1273: Phosphorus is stored under water to prevent it from Options:
  A) Dehydrating
  B) Becoming inert
  C) Smelling
  D) Catching fire
  Show Answer
  The correct answer is D .
• Question 1274: Ethanol is soluble in water due to the presence of a Options:
  A) Carbonyl group
  B) Hydroxyl groupd
  C) Phenyl group
  D) Methyl group
  Show Answer
  The correct answer is B .
• Question 1275: Which of the following metals is passive to concentrated trioxonitrate (V) acid? Options:
  A) Iron
  B) Tin
  C) Copper
  D) Zinc
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  The correct answer is A .
• Question 1276:

  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 1277:

  When ammonia and hydrogen ion bond together to form ammonium ion, the bond formed is called

  Options:
  A) electrovalent bond
  B) co-ordinate bond
  C) ionic bond
  D) covalent bond
  Show Answer
  The correct answer is B .
• Question 1278:

  Which of the following is a non-metal that remains liquid at room temperature?

  Options:
  A) Chlorine
  B) Phosphorus
  C) Bromine
  D) Helium
  Show Answer
  The correct answer is C .
• Question 1279:

  

  In the graph above, the activation energy of the catalyzed reaction is

  Options:
  A) 100KJ
  B) 300KJ
  C) 250KJ
  D) 200KJ
  Show Answer
  The correct answer is A .
• Question 1280:

  An organic compound contains 69% carbon, 15.3% hydrogen and 30.7% oxygen. Calculate the the empirical formula [C=12, H = 1, O = 16]

  Options:
  A) C${}_4$H${}_{1}2$O
  B) C${}_3$H${}_9$O
  C) C${}_4$H${}_9$O
  D) C${}_3$H${}_8$O
  Show Answer
  The correct answer is D .