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 501:

  

  The diagram shown above represents the solubility curves of two salts, X and Y, in water, use this diagram to answer the question. At room temperature (300 K)

  Options:
  A) Y is twice as soluble as X
  B) X is twice as soluble as Y
  C) X and Y are soluble to the same extent
  D) X is three times as soluble as Y
  E) Y is three times as soluble as X
  Show Answer
  The correct answer is A .
• Question 502: A noble gas with a high power of fog penetration used in aerodrome beacons is Options:
  A) krpton
  B) argon
  C) helium
  D) neon
  Show Answer
  The correct answer is D .
• Question 503: What is the volume of oxygen required to burn complete 45 cm³ of methane at s.t.p? Options:
  A) 135.0 cm³
  B) 180.0 cm³
  C) 45.0 cm³
  D) 90.0 cm³
  Show Answer
  The correct answer is D .
• Question 504: Which of the following best explains the increase in the rate of a chemical reaction as the temperature rises? Options:
  A) The bonds in the reacting molecules are more readily broken
  B) The molecular collisions become more violent
  C) A lower proportion of the molecules has the necessary minimum energy to react
  D) The collision frequency of the molecules increase
  Show Answer
  The correct answer is D .
• Question 505: 0.499g 0f CuSO₄.xH₂O when heated to constant weight gave a residue of 0.346g. the value of x is? (Cu = 63.5, S = 32.0, O = 16, H = 1) Options:
  A) 0.5
  B) 2.0
  C) 3.0
  D) 4.0
  E) 5.0
  Show Answer
  The correct answer is D .
• Question 506:

  The most abundant rare gas in the atmosphere is?

  Options:
  A) He
  B) Ne
  C) Ar
  D) Xe
  Show Answer
  The correct answer is C .
• Question 507: Which one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series? Options:
  A) Copper
  B) Iron
  C) Lead
  D) Potassium
  E) Zinc
  Show Answer
  The correct answer is D .
• Question 508: 0.1 Faraday of electricity was passed through a solution of copper (ll) sulphate. The maximum weight of copper deposited on the cathode would be [Cu = 64] Options:
  A) 64.0g
  B) 32.0g
  C) 16.0g
  D) 6.4 g
  E) 3.2g
  Show Answer
  The correct answer is E .
• Question 509: What is observed when aqueous solutions of each of tetraoxosulphate (VI) acid, potassium trioxoiodate (V) and potassium iodide are mixed together? Options:
  A) A white precipitate is formed
  B) A green precipitate is formed
  C) The mixture remains colourless
  D) The mixture turns reddish brown
  Show Answer
  The correct answer is D .
• Question 510:

  Which of the following is used to power steam engines?

  Options:
  A) lubricating oil
  B) coal
  C) bitumen
  D) diesel oil
  Show Answer
  The correct answer is B .