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 401: A quantity of air was passed through a weighed amount of alkaline pyrogallol. An increase in the weight of the pyrogallol would result from the absorption of? Options:
  A) nitrogen
  B) neon
  C) argon
  D) oxygen
  Show Answer
  The correct answer is D .
• Question 402: C_xH_Y + 4O₂ → 3CO₂ + 2H₂O. The hydrocarbon, C_xH_Y, in the reaction above is? Options:
  A) propane
  B) propene
  C) propyne
  D) propanone
  Show Answer
  The correct answer is C .
• Question 403: 9.8g of solid potassium chlorate (KCIO₃) were added to 40 cm³ of water and heated to dissolve all the solid. As he solution cooled, crystals of potassium chlorate started forming at 60°C. The solubility of potassium chlorate at 66°C is therefore? Options:
  A) 24.5 mole per dm³
  B) 0.2 mole per dm³
  C) 10.0 mole per dm³
  D) 20.0 mole per dm³
  E) 2.0 mole per dm³
  Show Answer
  The correct answer is E .
• Question 404: Sodium chloride has no solubility product value because of its? Options:
  A) saline nature
  B) high solubility
  C) low solubility
  D) insolubility
  Show Answer
  The correct answer is B .
• Question 405:

  Chromatography is used to separate components of mixture which differ in their rates of ?

  Options:
  A) diffusion
  B) migration
  C) reaction
  D) sedimentation
  Show Answer
  The correct answer is B .
• Question 406:

  The reactivity of fluorine is due to?

  Options:
  A) its high electro negativity
  B) small size of fluorine atom
  C) availability of D-orbitals
  D) strong f-f bond
  Show Answer
  The correct answer is A .
• Question 407: When air is compressed? Options:
  A) its density decreases
  B) it solidifies
  C) its temperature decreases
  D) its temperature increases
  E) its temperature remains unchanged
  Show Answer
  The correct answer is C .
• Question 408:

  

  What is the IUPAC name for the compound?

  Options:
  A) 1-chloro-2-methylprop-2,3-ene
  B) 1-chloro-2-methylprop-2-ene
  C) 3-chloro-2-methylprop-1-ene
  D) 3-chloro-2methylprop-1,2-ene
  Show Answer
  The correct answer is C .
• Question 409: Which of the following types of alkanols undergo oxidation to produce alkanoic acids? 1. Primary alkanols 11. Secondary alkanols 111. Tertiary alkanols Options:
  A) 1,11 and 111
  B) l and ll only
  C) ll only
  D) l only
  Show Answer
  The correct answer is D .
• Question 410: The alkaline hydrolysis of fats and oils produces soap and Options:
  A) propane 1, 1, 3 - triol
  B) propane - 1,2,3 - triol
  C) propane - 1,3,3 - triol
  D) propane - 1, 2, 2 - triol
  Show Answer
  The correct answer is B .