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 841: The type of reaction that is peculiar to benzene is Options:
  A) addition
  B) hydrolysis
  C) polymerization
  D) substitution
  Show Answer
  The correct answer is D .
• Question 842:

  N${}_2$O${}_4$⇔ 2NO${}_2$ ( = -ve)

  From the reaction above, which of these conditions would produce the highest equilibrium yield forN${}_2$O${}_4$?

  Options:
  A) Low temperature and high pressure
  B) Low temperature and low pressure
  C) high temperature and low pressure
  D) high temperature and high pressure
  Show Answer
  The correct answer is A .
• Question 843: The four classes of hydrocarbons are? Options:
  A) ethane, ethene, ethyne and benzene
  B) alkanes, alkenes, alkynes and aromatics
  C) alkanes, alkenes, alkynes and benzene
  D) methane, ethane , propane and butane
  Show Answer
  The correct answer is B .
• Question 844: How many cations will be produced from a solution of potassium aluminium tetraoxosulphate (VI)? Options:
  A) 3
  B) 4
  C) 1
  D) 2
  Show Answer
  The correct answer is D .
• Question 845:

  

  What is the IUPAC name for the compound?

  Options:
  A) 1-chloro-2-methylprop-2,3-ene
  B) 1-chloro-2-methylprop-2-ene
  C) 3-chloro-2-methylprop-1-ene
  D) 3-chloro-2methylprop-1,2-ene
  Show Answer
  The correct answer is C .
• Question 846: Which of these represents a redox reaction? Options:
  A) AgNO₃ + NaCl → AgCAl + NaNO₃
  B) H₂S + Pb(NO₃) → PbS + 2HNO₃
  C) CaCO₃ → CaO + CO₂
  D) Zn + 2HCl → ZnCl₂ + H₂
  Show Answer
  The correct answer is D .
• Question 847: Nuclear fission involves the splitting of a heavy element into two nuclei of Options:
  A) nearly equal masses with a relaese of energy and radiaton
  B) equal masses with a relaese of energy
  C) equal masses with a release of energy and radiation
  D) unequal masses without any relaese of energy
  Show Answer
  The correct answer is A .
• Question 848:

  Hydrogen diffused through a porous plug

  Options:
  A) thrice as fast as oxygen
  B) at the same speed as oxygen
  C) four times as fast as oxygen
  D) twice as fast as oxygen
  Show Answer
  The correct answer is C .
• Question 849: A silicon -containing ore has 92% ²⁸Si, 5% ²⁹Si and 3% ³⁰Si. Calculate the relative atomic mass of the silicon. Options:
  A) 14.00
  B) 29.00
  C) 28.11
  D) 28.00
  Show Answer
  The correct answer is C .
• Question 850: which of the following gives a precipitate when treated with NaOH solution? Options:
  A) AlCl₃
  B) NH₄Cl
  C) Na₂CO₃
  D) CH₃COONa
  Show Answer
  The correct answer is A .