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 951: Which of the following metals is passive to concentrated trioxonitrate (V) acid? Options:
  A) Iron
  B) Tin
  C) Copper
  D) Zinc
  Show Answer
  The correct answer is A .
• Question 952:

  Which of the following factors will speed up the rate of evolution of carbon (iv) oxide in the reaction below?

  2HCl + CaCO${}_3$ → CaCl${}_2$ + H${}_2$O + CO${}_2$

  Options:
  A) Increasing the concentration of the acid
  B) Increasing the surface area of CaCO${}_3$
  C) A and B
  D) Reducing the concentration of the acid
  Show Answer
  The correct answer is C .
• Question 953:

  The oxidation state(s) of nitrogen in ammonium nitrite is/are

  Options:
  A) -3, +3
  B) +5
  C) -3, +5
  D) -3
  Show Answer
  The correct answer is A .
• Question 954: An elements X with relative atomic mass 16.2 contains two isotopes ¹⁶₈X with relative abundance of 90% and ^m₈X with relative abundance of 10%. The value of m is Options:
  A) 16
  B) 18
  C) 12
  D) 14
  Show Answer
  The correct answer is B .
• Question 955: The molecular lattice of iodine is held together by Options:
  A) dative bond
  B) metallic bond
  C) hydrogen bond
  D) van der Waal's forces
  Show Answer
  The correct answer is D .
• Question 956:

  56.00cm³ of a gas at S.T.P. weighed 0.11g. What is the vapour density of the gas?
  [Molar volume of a gas at S.T.P = 22.4dm³]

  Options:
  A) 11.00
  B) 22.00
  C) 33.00
  D) 44.00
  Show Answer
  The correct answer is B .
• Question 957:

  Which of the following statements is true for strong electrolytes?

  Options:
  A) They do not conduct electricity in the molten state
  B) They completely dissociate into ions in solution
  C) They are non-polar substances
  D) They partially dissociate into ions in solution
  Show Answer
  The correct answer is B .
• Question 958:

  What type of reaction is involved in the formation of alkanols from alkenes?

  Options:
  A) Elimination reaction
  B) Redox reaction
  C) Substitution reaction
  D) Addition reaction
  Show Answer
  The correct answer is D .
• Question 959: Which of the following are structural isomers? Options:
  A) propanoic acid and propan-1, 2-diol
  B) Propanal and propanone
  C) Ethanoic acid and propanoic acid
  D) Ethan-1, 2-diol and ethanoic acid
  Show Answer
  The correct answer is B .
• Question 960:

  If gas A has a molar mass of 32 g/mol and gas B has a molar mass of 64 g/mol, what is the ratio of their diffusion rates?

  Options:
  A) 2:1
  B) 1:2
  C) 1:1
  D) 1:4
  Show Answer
  The correct answer is A .