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 1721:

  Give the common name for the following compound (CH${}_3$)${}_2$ CH CH${}_2$ -Br

  Options:
  A) Isobutyl bromide
  B) Methyl bromide
  C) propyl bromide
  D) Butyl bromide
  Show Answer
  The correct answer is A .
• Question 1722:

  .....................P....Q.....R......S

  Proton..............13....16....17.....19

  Electron............13....16....17.....19

  Neutron.............14....16....35.....20Which of the four atoms P,q,R and in S in the above data can be described by the following properties relative atomic mass is greater than 30 but less than 40; it has an odd atomic number and forms a unipositive ion in solution?

  Options:
  A) P
  B) Q
  C) R
  D) S
  Show Answer
  The correct answer is D .
• Question 1723:

  What technique is suitable for separating a binary solution of potassium chloride and potassium trioxochlorate (V)?

  Options:
  A) Fractional crystallization
  B) Fractional distillation
  C) Filtration
  D) Evaporation
  Show Answer
  The correct answer is A .
• Question 1724: Which of the following terms indicates the number of bonds that can be formed by an atom? Options:
  A) Oxidation number
  B) Valence
  C) Atomic number
  D) Electronegativity
  Show Answer
  The correct answer is B .
• Question 1725: Which of the following methods can be used to obtain pure water from a mixture of sand, water and methanoic acid? Options:
  A) netralization with NaOHfoolowed by filtration
  B) neutralization with NaOH followed by distillation
  C) fractional distillation
  D) filtration followed by distillation
  Show Answer
  The correct answer is D .
• Question 1726:

  

  The IUPAC nomenclature of the organic compound with the above structural formula is

  Options:
  A) 3-ethyl-2,5-dimethylhexane
  B) 4-ethyl-2,5-dimethylhexane
  C) 3-ethyl-2,5,5 - trimethylpentane
  D) 3-ethyl, 1,1,4-trimethylpentane
  Show Answer
  The correct answer is A .
• Question 1727: The impurities formed during the laboratory preparation of chlorine gas are removed by Options:
  A) H₂O
  B) NH₃
  C) H₂SO₄
  D) HCl
  Show Answer
  The correct answer is A .
• Question 1728: Cathode rays cause an object placed behind a perforated anode to cast a shadow on the screen. This observation shows that the rays Options:
  A) are positively charged
  B) are negatively charged
  C) Have mass
  D) travel in straight lines
  Show Answer
  The correct answer is D .
• Question 1729: Which of the following compounds would give lilac flame coloration and a white precipitate with acidified barium chloride solution? Options:
  A) KCI
  B) NaNO₃
  C) K₂SO₄
  D) CaSO₄
  Show Answer
  The correct answer is C .
• Question 1730:

  

  In the diagram above, which of the curves represents the evolution of oxygen with time in the equation 2KClO_3(s) → 2KCl_(s) + 3O_2(g)?

  Options:
  A) X
  B) Y
  C) Z
  D) R
  Show Answer
  The correct answer is C .