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: When sodium trioxocarbonate (IV) decahydrate loses its water of crystallization to the atmosphere, the process is Options:
  A) deliquescence
  B) efflorescence
  C) hygroscopic
  D) effervesecence
  Show Answer
  The correct answer is B .
• Question 1312: An acid is said to be weak if? Options:
  A) its ions are so completely dissociated that they easily drift apart
  B) the acid is not corrosive
  C) the acid has low specific gravity
  D) its ions move very slowly when in solution
  E) its ions are incompletely dissociated
  Show Answer
  The correct answer is E .
• Question 1313:

  56.00cm³ of a gas at S.T.P. weighed 0.11g. What is the vapour density of the gas?

  [Molar volume of a gas at S.T.P = 22.4dm³]

  Options:
  A) 11.00
  B) 22.00
  C) 33.00
  D) 44.00
  Show Answer
  The correct answer is B .
• Question 1314:

  What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?

  [H = 1, O = 16]

  Options:
  A) 36.0g
  B) 8.0g
  C) 72.0g
  D) 16.0g
  Show Answer
  The correct answer is C .
• Question 1315:

  16.8 g of sodium hydrogen trioxocarbonate (IV) is completely decomposed by heat. Calculate the volume of carbon(IV) oxide given off s.t.p

  [Na 23, C = 12, O = 16, H = 1, Molar volume of a gas at s.t.p = 22.4 dm³]

  Options:
  A) 22.40 dm³
  B) 11.20 dm³
  C) 2.24 dm³
  D) 1.12 dm³
  Show Answer
  The correct answer is C .
• Question 1316: What is the decrease in volume of air when pyrogallol is shaken with 30.00cm³ of air ? Options:
  A) 15.00cm³
  B) 6.30cm³
  C) 0.63cm³
  D) 0.06cm³
  Show Answer
  The correct answer is B .
• Question 1317:

  

  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 1318:

  

  The graph above demonstrate the effect of

  Options:
  A) surface area on the rate of reaction
  B) catalyst on the rate of reaction
  C) pressure on the rate reaction
  D) concentration on the rate of reaction
  Show Answer
  The correct answer is A .
• Question 1319: In a water body, too much sewage leads to Options:
  A) a decrease in the temperature of the water which cause in death of aquatic animals
  B) an increase in the number of aquatic animals in the water
  C) an increase in the bacterial population which reduces the level of oxygen in the water
  D) a decrease in the bacterial population which increases the level of oxygen in the water
  Show Answer
  The correct answer is C .
• Question 1320: When sodium reacts with water, the resulting solution is Options:
  A) Weakly acidic
  B) Neutral
  C) Acidic
  D) Alkaline
  Show Answer
  The correct answer is D .