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 2251: Which of the following reagents will confirm the presence of unsaturation in a compound? Options:
  A) Fehling's solution
  B) Bromine water
  C) Tollen's reagent
  D) Benedict's solution
  Show Answer
  The correct answer is B .
• Question 2252: Which of the following are isomers? Options:
  A) Ethanol and dimethyl ether
  B) Benzene and methybenzene
  C) Ethanol and propanone
  D) Trichloromethane and tetrachloromethane
  Show Answer
  The correct answer is A .
• Question 2253:

  In the laboratory preparation of oxygen, the gas cannot be collected by displacement of air because

  Options:
  A) the density of oxygen is greater than that of air
  B) the density of air is nearly the same as that of oxygen
  C) oxygen is a component of air
  D) air is an impure substance
  Show Answer
  The correct answer is A .
• Question 2254: The mass of silver deposited when a current of 10A is passed through a solution of silver salt for 4830s is – (Ag = 108 F = 96500(mol^-1) Options:
  A) 54.0g
  B) 27.0g
  C) 13.5g
  D) 108.0g
  Show Answer
  The correct answer is A .
• Question 2255: Ethene reacts with hydrogen bromide to give Options:
  A) CH₂Br₂
  B) CH₃CH₂Br
  C) C₂H₂Br₂
  D) CHBr₂
  Show Answer
  The correct answer is B .
• Question 2256: Pick out the correct statement Options:
  A) Zin heated to redness reacts with steam to give oxygen and zinc oxide
  B) Zinc heated to redness reacts with steam to give oxygen and hydrogen
  C) Zinc does not react with hot or cold water
  D) Zinc reacts with hot water to form zinc oxide and hydrogen
  E) Zinc reacts very easily with cold water to give zinc oxide and hydrogen
  Show Answer
  The correct answer is D .
• Question 2257:

  The alkanoic acid found in human sweat is

  Options:
  A) CH${}_3$-COOH
  B) CH${}_3$—CH${}_2$—COOH
  C) H-COOH
  D) CH${}_3$
  Show Answer
  The correct answer is B .
• Question 2258:

  Alkanol + Alkanoic ↔ Ester + Water

  The reverse reaction above is known as

  Options:
  A) Hydrolysis
  B) Saponification
  C) Hydration
  D) Fermentation
  Show Answer
  The correct answer is A .
• Question 2259:

  The shape of ammonia molecule is?

  Options:
  A) Trigonal planar
  B) Octahedral
  C) Square planar
  D) Tetrahedral
  Show Answer
  The correct answer is A .
• Question 2260:

  

  The compound above exhibits

  Options:
  A) geometric isomerism
  B) optical isomerism
  C) structural isomerism
  D) positional isomerism
  Show Answer
  The correct answer is B .