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 711: 30 cm³ of 0.1 M Al (NO₃)₃ SOLUTION IS RECTED WITH 100cm³ of 0.15M of NaOH solution. Which reactant is in excess, and by now much ? Options:
  A) NaOH solution by 70 cm³
  B) NaOH solution, by 60 cm³
  C) NaOH solution by 40 cm³
  D) Al(NO₃)₃ solution by 20 cm³
  E) Al(NO₃)₃ solution by 10 cm³
  Show Answer
  The correct answer is C .
• Question 712: The principle of column chromatography is based on the ability of the constituents to Options:
  A) move at different speeds in the column
  B) dissolve in each other in the column
  C) react with the solvent in the column
  D) react with each other in the column
  Show Answer
  The correct answer is A .
• Question 713: The pair of metals in the reactivity series that are usually extracted by the electrolysis of their ores is Options:
  A) magnesium and zinc
  B) magnesium and calcium
  C) copper and zinc
  D) lead and calcium
  Show Answer
  The correct answer is B .
• Question 714:

  Alkanes are used mainly?

  Options:
  A) in the textile industry
  B) in the hydrogenation of oils
  C) as domestic and industrial fuels
  D) as fine chemicals
  Show Answer
  The correct answer is C .
• Question 715: 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 716: The isomers of C₃H₈O ARE Options:
  A) 1 - propanol and 2 - propanol
  B) 1 - propanol and 1 - propanol
  C) 2 - propanol and 2 - propanone
  D) 2 - propanol and 1 - propanol
  Show Answer
  The correct answer is A .
• Question 717:

  The inherited traits of an organism are controlled by?

  Options:
  A) RNA molecules
  B) Nucleotides
  C) DNA molecules
  D) Enzymes
  Show Answer
  The correct answer is C .
• Question 718:

  N₂O_4(aq) $\rightleftharpoons$ 2NO_2(g) $△$H = +ve

  In the reaction above, an increase in temperature will

  Options:
  A) Increase the reactant production
  B) Increase the value of the equilibrium constant
  C) Shift the equilibrium to the left
  D) Decrease the value of the equilibrium constant
  Show Answer
  The correct answer is B .
• Question 719: A metal X forms two bromides with the formulae XBr₂ and XBr₃. What type of bonding exists between X and bromine in the bromide? Options:
  A) Ionic bonding
  B) Metallic bonding
  C) Dative bonding
  D) Covalent bonding
  Show Answer
  The correct answer is A .
• Question 720: Two equal bulbs, one containing ammonia and the other one opened mouth-to mouth to each other at temperature the entropy in the mixture of gases is likely to Options:
  A) remain unchanged
  B) increase
  C) decrease
  D) charge
  Show Answer
  The correct answer is A .