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 1841: N₂O_4(g) ↔ 2NO_2(g). Increase in total pressure of the equilibrium reaction above will Options:
  A) produce more of NO_2(g) in the mixture
  B) convert all of N₂O_4(g) to NO_2(g)
  C) have no effect on the concentrations of NO_2(g)and N₂O_4(g)
  D) produce more of N₂O_4(g) in the mixture
  Show Answer
  The correct answer is D .
• Question 1842: The colour imparted to a flame by calcuium ion is Options:
  A) green
  B) blue
  C) brick-red
  D) yellow
  E) lilac
  Show Answer
  The correct answer is C .
• Question 1843: Which of the following statement is true of a proton? Options:
  A) The mass of a proton is 1840 times the mass of electron
  B) the total mass of the protons in a particular nucleus is always half the nuclear size
  C) The mass of a proton is one - twelfth the molar mass of carbon
  D) The mass of a proton is 1.0008g
  Show Answer
  The correct answer is D .
• Question 1844: The relatively high boiling points of alkanols are due to? Options:
  A) ionic bonding
  B) aromatic character
  C) covalent bonding
  D) hydrogen bonding
  Show Answer
  The correct answer is D .
• Question 1845: The compound produced when sodium peroxide is heated with excess sodium is Options:
  A) Na₂CO₃
  B) Na₂O
  C) NaNO₂
  D) NaOH
  Show Answer
  The correct answer is B .
• Question 1846: 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 1847:

  When a solid substance disappears completely as a gas on heating, the substance is said to have undergone?

  Options:
  A) Sublimation
  B) Crystallization
  C) Distillation
  D) Evaporation
  Show Answer
  The correct answer is A .
• Question 1848:

  An organic compound that does not undergo a reaction with both hydrogen cyanide and hydroxylamine can be?

  Options:
  A) Alkene
  B) Alkanal
  C) Alkanone
  D) Alkanoic Acid
  Show Answer
  The correct answer is A .
• Question 1849: Which of the following is NOT an alkali? Options:
  A) NH₃
  B) Mg(OH)₂
  C) Ca(OH)₂
  D) NaOH
  Show Answer
  The correct answer is A .
• Question 1850: The effect of the presence of impurities such as carbon and sulphur on iron is that they Options:
  A) give it high tensile strenght
  B) make it malleable and ductile
  C) increase its melting point
  D) lower its melting point
  Show Answer
  The correct answer is D .