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 1311:

  

  The above diagram gives the potential energy profile of the catalyst and uncatalysed reactions of X_(g) + Y_(g) → XY_(g). Deduce the respective activation energies in KJ of the catalysed and uncatalysed reverse reactions: XY(g) → X_(g) + Y_(g)

  Options:
  A) 300, 500
  B) 500, 300
  C) -300, -500
  D) -500, -300
  Show Answer
  The correct answer is A .
• Question 1312:

  When air which contains the gases Oxygen, nitrogen, carbondioxide, water vapour and the rare gases, is passed through alkaline pyrogallol and then over quicklime, the only gases left are;

  Options:
  A) nitrogen and carbondioxide
  B) the rare gases
  C) nitrogen and oxygen
  D) nitrogen and the rare gases
  Show Answer
  The correct answer is D .
• Question 1313:

  What is the molar mass of water (H2O)?

  Options:
  A) 18 g/mol
  B) 22 g/mol
  C) 16 g/mol
  D) 12 g/mol
  Show Answer
  The correct answer is A .
• Question 1314:

  200cm³ each of 0.1M solutions of lead (II) trioxonitrate (V) and hydrochloric acid were mixed. Assuming that lead (II) chloride is completely insoluble, calculate the mass of lead (II) chloride that will be precipitated.

  [Pb = 207, Cl= 35.5, N = 14, O = 16]

  Options:
  A) 2.78g
  B) 5.56g
  C) 8.34g
  D) 11.12g
  Show Answer
  The correct answer is B .
• Question 1315:

  The IUPAC name of the compound CF${}_3$CHBrCl is

  Options:
  A) 2-chloro-2-bromo-1,1,1-trifluoroethane
  B) 2-bromo-2-chloro-1,1,1-trifluoroethane
  C) 1-bromo-1-chloro-2,2,2-trifluoroethane
  D) 1,1,1-trifluoro-2-bromo-2-chloroethane
  Show Answer
  The correct answer is B .
• Question 1316:

  The dehydration of CH${}_3$CH${}_2$CH${}_2$CH${}_2$OH will give?

  Options:
  A) HC≡CCH${}_2$CH${}_3$
  B) CH${}_2$≡CH${}_2$CH${}_3$
  C) CH${}_3$C≡CCH${}_3$
  D) CH${}_3$CH=CHCH${}_3$
  Show Answer
  The correct answer is D .
• Question 1317:

  What unit of temperature should be used when applying the ideal gas law?

  Options:
  A) Fahrenheit (°F)
  B) Kelvin (K)
  C) Rankine (°R)
  D) Celsius (°C)
  Show Answer
  The correct answer is B .
• Question 1318: The most suitable metal that can be used as lightning conductor is Options:
  A) silver
  B) copper
  C) iron
  D) aluminium
  Show Answer
  The correct answer is B .
• Question 1319: A jet plane carrying 3,000 kg of ethane burns off all the gas forming water and carbondioxide. if all the carbondioxide is expelled and all the water formed is condensed and kept on board the plane, then the gain in weight is Options:
  A) 1,800 kg
  B) 900 kg
  C) 600 kg
  D) 2, 400 kg
  E) 1, 200 kg
  Show Answer
  The correct answer is D .
• Question 1320:

  In the reaction between sodium hydroxide and sulphuric acid solutions, what volume of 0.5 molar sodium hydroxide would exactly neutralise 10cm3 of 1.25 molar sulphuric acid?

  Options:
  A) 5cm${}^3$
  B) 10cm${}^3$
  C) 20cm${}^3$
  D) 50cm${}^3$
  Show Answer
  The correct answer is D .