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 181: 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 182: A particle that contains 9 protons, 10 neutrons and 10 electrons is a Options:
  A) negative ion
  B) positive ion
  C) neutral atom of non-metal
  D) neutral atom of a metal
  Show Answer
  The correct answer is A .
• Question 183:

  When a substance is oxidized, it

  Options:
  A) Loses electrons
  B) Gains oxygen atoms
  C) Gains electrons
  D) Loses protons (H+ ions)
  Show Answer
  The correct answer is A .
• Question 184: A piece of filter paper moistened with lead (ll) ethanoate solution turns black when the paper is dropped into a gas likely to be Options:
  A) sulphur (VI) oxide
  B) hydrogen chloride
  C) sulphur (VI) oxide
  D) hydrogen sulphide
  Show Answer
  The correct answer is D .
• Question 185: A metal that forms soluble trioxosulphate (IV) ion is Options:
  A) barium
  B) potassium
  C) manganese
  D) aluminium
  Show Answer
  The correct answer is B .
• Question 186: The salt formed from a reaction between citric acid and sodium hydroxide in solution will be Options:
  A) acidic
  B) basic
  C) complex
  D) neutral
  Show Answer
  The correct answer is B .
• Question 187:

  The scientist who stated that matter can be converted into energy is?

  Options:
  A) Boyle
  B) Lavoiser
  C) Avogadro
  D) Einstein
  Show Answer
  The correct answer is D .
• Question 188:

  Which process(es) is/are involved in the turning of starch iodide paper blue-black by chlorine gas?

  Options:
  A) chlorine attacks the starch to give the blue-black color
  B) chlorine attacks the iodide ion to give the blue-black color
  C) chlorine oxidizes the iodide ion to produce iodine which attacks the starch to give the blue-black color
  D) iodine attacks the starch to give the blue-black color
  Show Answer
  The correct answer is C .
• Question 189:

  Zn + 2HCL ZnCl${}_2$ + H${}_2$

  What happens to zinc in the above reaction?

  Options:
  A) oxidized
  B) a reactant
  C) reduced
  D) a metal
  Show Answer
  The correct answer is A .
• Question 190: The bleaching action of chlorine gas is effective due to the presence of Options:
  A) hydrogen chloride
  B) water
  C) air
  D) oxygen
  Show Answer
  The correct answer is B .