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 741: Tin is unaffected by air at ordinary temperature due to its Options:
  A) Low melting point
  B) Weak electropositive character
  C) High boiling point
  D) White lustrous appearance
  Show Answer
  The correct answer is A .
• Question 742:

  Which of the following is a common laboratory indicator for bases?

  Options:
  A) Methyl orange
  B) Phenolphthalein
  C) Bromothymol blue
  D) Litmus
  Show Answer
  The correct answer is B .
• Question 743: Which of the following types of reactions takes place between C₂H₄ and the halogens? Options:
  A) Substitution
  B) Polymerization
  C) Addition
  D) Saponification
  E) Oxidation
  Show Answer
  The correct answer is C .
• Question 744: When pollen grains are suspended in water and viewed through a microscope, they appear to be in a state of constant but erratic motion. This is due to? Options:
  A) convection currents
  B) small changes
  C) small changes in temperature
  D) a chemical reaction between the pollen grain and water
  E) the bombardment of the pollen grains by molecules of water
  Show Answer
  The correct answer is E .
• Question 745: Phosphorus burns in oxygen according to the equation P₄ + 50₂ → P₄O₁₀. How many litres of oxygen will be required at S.T.P for complete oxidation of 12.4g of phosphorus? [P = 31,O = 16 and molar volume of a gas at S.T.P = 22.4 litres] Options:
  A) 5. 20
  B) 11. 20
  C) 2. 24
  D) 20. 20
  E) 6. 20
  Show Answer
  The correct answer is B .
• Question 746: The reaction between ethanoic acid and sodium hydroxide is an example of Options:
  A) esterification
  B) neutralization
  C) hydroxylation
  D) hydrolysis
  Show Answer
  The correct answer is B .
• Question 747: Catalytic hydrogenation of benzene produces Options:
  A) Oil
  B) Cyclohexene
  C) Cyclohexane
  D) Margarine
  Show Answer
  The correct answer is C .
• Question 748:

  

  The compound above exhibits

  Options:
  A) Geometric isomerism
  B) Positional isomerism
  C) Structural isomerism
  D) Optical isomerism
  Show Answer
  The correct answer is D .
• Question 749: Environmental pollution is worsened by the release from automobile exhausts of Options:
  A) Water vapour
  B) Steam
  C) Smoke
  D) Heavy metals
  Show Answer
  The correct answer is C .
• Question 750:

  N_2(g) + O_2(g) ↔ 2NO_(g); ΔH = + 180.6 kJ mol^-1

  In the reaction above, increase in temperature will

  Options:
  A) increase the quantity of N₂
  B) increase in the yield of NO
  C) decrease the yield of NO
  D) decrease the quantity of O₂
  Show Answer
  The correct answer is B .