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 2061: In titration involving sodium hydroxide and dilute hydrochloric acid, where would you place the base? Options:
  A) in the beaker
  B) in the conical flask
  C) in a burette
  D) in the standard flask
  E) in the measuring cylinder
  Show Answer
  The correct answer is B .
• Question 2062: Which of the following metals can be prepared in samples by the thermal decomposition of their trioxonitrate (V) salts? Options:
  A) Copper and mercury
  B) Silver and copper
  C) Mercury and silver
  D) Magnesium and mercury
  Show Answer
  The correct answer is C .
• Question 2063: A solution of calcium bromide contains 20 g dm ³ What is the molarity of the solution with respect to calcium bromide and bromide ions? [Ca = 40, Br = 80] Options:
  A) 0. 1, 0 . 1
  B) 0. 1, 0. 2
  C) 0. 1, 0. 05
  D) 0.05, 0.1
  Show Answer
  The correct answer is C .
• Question 2064:

  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 2065: There are basic particles from which matter called be made except Options:
  A) Salt
  B) Atom
  C) Ion
  D) Molecule
  Show Answer
  The correct answer is A .
• Question 2066:

  

  Use the solubility curves below to answer questions. If 1 dm³ of a saturated solution of L at 60⁰C is cooled to 25⁰C, what amount in mole will separate out?

  Options:
  A) 0.75
  B) 0.25
  C) 1.00
  D) 0.50
  Show Answer
  The correct answer is A .
• Question 2067:

  Addition of sodium chloride to water to form a solution would lead to?

  Options:
  A) increase in freezing point and increase the boiling point
  B) increase in freezing point and decrease the boiling point
  C) decrease in freezing point and decrease the boiling point
  D) decrease in freezing point and increase the boiling point
  Show Answer
  The correct answer is D .
• Question 2068:

  1s², 2s², 2p⁶, 3s², 3p⁶, 3d⁷, 4s²

  An element with the electronic configuration above is a

  Options:
  A) non-metal
  B) metal
  C) transition element
  D) group two element
  Show Answer
  The correct answer is C .
• Question 2069: Which of the following equations show that a reaction is in equilibrium?
  Options:
  A) ΔG < O
  B) ΔG = ΔH – TΔS
  C) ΔG > O
  D) ΔG = O
  Show Answer
  The correct answer is D .
• Question 2070:

  When water drops are added to calcium carbide in a container and the gas produced is passed through a jet and lighted, the resultant flame is called an?

  Options:
  A) Oxyethene
  B) Oxyhydrocarbon flame
  C) Oxyacetylene flame
  D) Oxymethane flame
  Show Answer
  The correct answer is C .