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 1501: If 0.75 mole of cyclopropane and 0.66 mole of oxygen are mixed in vessel with a total pressure of 0.7 atmosphere, what is the partial pressure of oxygen in the mixture Options:
  A) 0.44 atmosphere
  B) 0.22 atmosphere
  C) 0.55 atmosphere
  D) 0.33 atmosphere
  Show Answer
  The correct answer is D .
• Question 1502: Four elements P,Q, R and S have atomic numbers of 4, 10, 12 and 14 respectively . Which of these electrons is a noble gas? Options:
  A) P
  B) Q
  C) R
  D) S
  Show Answer
  The correct answer is B .
• Question 1503: Gunpower is made from charcoal, sulphur and potassium trioxonitrate (V) The salt in the mixture performs the function of Options:
  A) an oxidant
  B) a reductant
  C) a solvent
  D) a catalyst
  Show Answer
  The correct answer is A .
• Question 1504:

  What is eutrophication?

  Options:
  A) The release of harmful chemicals into water bodies
  B) The excessive growth of algae due to nutrient enrichment
  C) The presence of heavy metals in water
  D) The formation of oil slicks on water surfaces
  Show Answer
  The correct answer is B .
• Question 1505: Hydration of ions in solution is associated with Options:
  A) absorption of heat
  B) reduction of heat
  C) conduction of heat
  D) liberation of heat
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  The correct answer is D .
• Question 1506: Which of the aqueous solutions with the pH values below will liberate hydrogen when it react with magnesium metals? Options:
  A) 13.0
  B) 7.0
  C) 6.5
  D) 3.0
  Show Answer
  The correct answer is D .
• Question 1507: In what respect will two dry samples of nitrogen gas differ from each other if sample 1 is prepared by completely removing CO₂ and O₂ from air, and sample 2 is prepared by passing purified nitrogen(i)oxide over heated copper? sample 1 is Options:
  A) purer than sample 2
  B) slightly denser than sample 2
  C) in all respects the same as sample 2
  D) colourless but sample 2 has a light brown colour
  E) slightly less reactive than sample 2
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  The correct answer is B .
• Question 1508:

  By what amount must the temperature of 200cm${}^3$ of Nitrogen at 27°C be increased to double the pressure if the final volume is 150cm${}^3$ (Assume ideality)

  Options:
  A) 150°C
  B) 177°C
  C) 75°C
  D) 120°C
  Show Answer
  The correct answer is B .
• Question 1509: A heterogenous mixture can be defined as any mixture Options:
  A) of a solute nd a solvent
  B) whose cmposition is uniform
  C) whose composition is not uniform
  D) formed by solids and liquids
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  The correct answer is C .
• Question 1510: Deliquescent substance are used for Options:
  A) Cooling
  B) Wetting
  C) Melting
  D) Drying
  Show Answer
  The correct answer is D .