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 581:

  

  It can be deduced that the rate of the reaction

  Options:
  A) for bath l is higher than path ll
  B) for path ll is higher than path l
  C) is the same for both paths at all temperatures
  D) depends on the values of both x and y at all pressures
  Show Answer
  The correct answer is B .
• Question 582: Which of the following is a property of ionic chlorides? Options:
  A) They can be decomposed by heat
  B) They react with aqueous AgNO₃ to give a white precipiate which is soluble in excess ammonia
  C) They explode when in contact with dry ammonia
  D) They react with concentrated tetraoxosulphate (IV) acid to give white fumes of chlorine gas
  Show Answer
  The correct answer is B .
• Question 583:

  Which of the following metals cannot replace hydrogen from water or steam?

  Options:
  A) Sodium
  B) Magnesium
  C) Iron
  D) Calcium
  Show Answer
  The correct answer is D .
• Question 584:

  2Na_(s) + 2H₂O_(l) → 2NaOH_(aq) + H_2(g)

  From the equation above, calculate the mass of sodium hydroxide produced by 2.3g of sodium.

  [H = 1, O = 16, Na = 23]

  Options:
  A) 0.40g
  B) 0.80g
  C) 4.00g
  D) 8.00g
  Show Answer
  The correct answer is C .
• Question 585: The most common ores of iron include Options:
  A) haematite, malachite and limonite
  B) chalcolite, calamine and bornite
  C) magnetite, haematite and bornite
  D) magnetite, chalcolite and bornite
  Show Answer
  The correct answer is C .
• Question 586: When a piece of charcoal enclosed in a cylinder containing air is ignited Options:
  A) the toatl volume of air is increased
  B) the relative amount of oxygen present is increased
  C) the relative amount of nitrogen present is decreased
  D) the relative amount of carbondioxide present is increased
  E) the ratio of oxygen to nitrogen in the system is increased
  Show Answer
  The correct answer is D .
• Question 587: If 24.83 cm³ of 0.15 M NaOH is titrated to its end point with 39.45 cm³ of HCl, what is the molarity of the HCl? Options:
  A) 0.094 M
  B) 0.150 M
  C) 0.940 M
  D) 1.500 M
  Show Answer
  The correct answer is A .
• Question 588:

  Which of the following gases will diffuse fastest when passed through a porous plug?

  [H = 1, C = 12, N = 14, O = 16]

  Options:
  A) Propane
  B) Oxygen
  C) Methane
  D) Ammonia
  Show Answer
  The correct answer is C .
• Question 589: The solubility product of Cu(IO₃)₂ is 1.08 * 10^-7. Assuming that neither ions react appreciable with water to form H⁺ and OH^-, what is the solubility of this salt? Options:
  A) 2.7 * 10^-8 mol dm^-3
  B) 9.0 * 10^-8 mol dm^-3
  C) 3.0 * 10^-3 mol dm^-3
  D) 9.0 * 10^-3 mol dm^-3
  Show Answer
  The correct answer is D .
• Question 590: The approximate volume of air containing 10cm³ of oxygen is? Options:
  A) 20 cm³
  B) 25 cm³
  C) 50 cm³
  D) 100 cm³
  Show Answer
  The correct answer is C .