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 731: An example of an acidic oxide is Options:
  A) NO
  B) CO
  C) SO₂
  D) CuO
  Show Answer
  The correct answer is C .
• Question 732: Coal fire should not be used in poorly ventilated rooms because ? Options:
  A) of the accumulation of CO₂ which causes dep sleep
  B) it is usually too hot
  C) of the acumulation of CO which causes suffocation
  D) it removes most most of the gases in the rooms
  Show Answer
  The correct answer is C .
• Question 733: For a general equation of the nature xP + yQ ≈ mR + nS, the expression for the equilibrium constant is? Options:
  A) k (p)^x (Q)^y
  B) (p)^x (Q)^y / (R)^m (S)ⁿ
  C) (R)^m (S)ⁿ / (p)^x (Q)^y
  D) m(R) n (S) / x(P) y (Q)
  Show Answer
  The correct answer is C .
• Question 734:

  The IUPAC nomenclature of the compound

  H${}_3$C - CH(CH${}_3$) - CH(CH${}_3$) - CH${}_2$ - CH${}_3$

  Options:
  A) 3,4- dimethylhexane
  B) 2,3- dimethyl pentane
  C) 2- ethyl hexane
  D) 2,3- dimethylhexane
  Show Answer
  The correct answer is B .
• Question 735: Natural water collected from rivers and ponds contain oxygen, carbon (IV) oxide and Options:
  A) nitrogen
  B) hydrogen
  C) chlorine
  D) sulphur
  E) oxide
  Show Answer
  The correct answer is A .
• Question 736: The tincture of iodine means iodine dissolved in Options:
  A) ethanol
  B) bromine chloride
  C) chlorine water
  D) water
  Show Answer
  The correct answer is A .
• Question 737:

  Elements X and Y have electronic configurations 1s${}^2$2s${}^2$2p${}^4$ and 1s${}^2$2s${}^2$2p${}^6$3s${}^2$3p${}^1$ respectively. When they combine, the formula of the compound formed is

  Options:
  A) XY
  B) X${}_2$Y
  C) Y${}_2$X${}_3$
  D) X${}_2$Y${}_3$
  Show Answer
  The correct answer is C .
• Question 738: The gasification of coke is used for the manufacturing of Options:
  A) producer gas
  B) natural gas
  C) synthetic gas
  D) industrial gas
  Show Answer
  The correct answer is C .
• Question 739: The pollutant that contributes to the depletion of the ozone layer is Options:
  A) CFCs
  B) NO₂
  C) SO₂
  D) CO
  Show Answer
  The correct answer is A .
• Question 740: The Avogadro number of 24g of magnesium is the same as that of Options:
  A) 1g of hydrogen molecules
  B) 16g of oxygen molecules
  C) 32g of oxygen molecules
  D) 35.5g of chlorine molecules
  Show Answer
  The correct answer is C .