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 2221:

  ²²⁶₈₈Ra → ^x₈₆Rn + α - particle

  What is the value of x in the nuclear reaction above?

  Options:
  A) 220
  B) 222
  C) 226
  D) 227
  Show Answer
  The correct answer is B .
• Question 2222: CaO_s + H₂O_(l) → Ca(OH)_2(s) ΔH -65 kj. The process represented by the above equation is known as? Options:
  A) dissolution
  B) slaking
  C) liming
  D) mortaring
  Show Answer
  The correct answer is B .
• Question 2223: An amphoteric oxide is an? Options:
  A) amorphous oxide of a metal
  B) amorphous oxide of a non-mental
  C) oxide that is insoluble in water
  D) oxide that behaves both as a base as well as an acid
  E) oxide that loses its oxygen on sublimation
  Show Answer
  The correct answer is D .
• Question 2224: When dissolved in water, NaOH flakes show Options:
  A) An endothermic change
  B) An exothermic change
  C) A slow reaction
  D) A rapid reaction
  Show Answer
  The correct answer is B .
• Question 2225: What is the consequences of increasing pressure on the equilibrium reaction ZnO_(s) + H_2(g) Zn_(s) + H₂O_(I)? Options:
  A) The equilibrium is driven to the left
  B) The equilibrium is driven to the right
  C) There is no effect
  D) More ZnO is produced
  Show Answer
  The correct answer is C .
• Question 2226: The boiling point of water is higher than that of methanol because? Options:
  A) water is oxide while methanol is an alcohol
  B) inter molecular forces in water are stronger than those in methanol
  C) water is an inorganic compound while methanol is organic
  D) water is an ionic compound while methanol is a covalent compound
  E) water is more reactive than methanol
  Show Answer
  The correct answer is B .
• Question 2227: The distance between the nuclei of chlorine atoms in a chlorine molecule is 0.194nm. The atomic radius of chlorine atom is Options:
  A) 0.097nm
  B) 0.914nm
  C) 0.388nm
  D) 2.388nm
  Show Answer
  The correct answer is A .
• Question 2228: When sodium trioxocarbonate (IV) decahydrate loses its water of crystallization to the atmosphere, the process is Options:
  A) deliquescence
  B) efflorescence
  C) hygroscopic
  D) effervesecence
  Show Answer
  The correct answer is B .
• Question 2229:

  

  Use the diagram to answer this question.

  The gas that can be used to demonstrate the experiment is

  Options:
  A) hydrogen chloride
  B) hydrogen sulphide
  C) nitrogen(ll) oxide
  D) dinitrogen (l) oxide
  Show Answer
  The correct answer is A .
• Question 2230:

  At 25^o and zymase as catalyst,

  C₆H₁₂₆ → 2C₂H₅OH + 2CO₂ + energy

  The reaction above represented by the equation above is useful in the production of

  Options:
  A) propanol
  B) butanol
  C) methanol
  D) ethanol
  Show Answer
  The correct answer is D .