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 161: Which one of the following metals is not normally extracted by chemical reduction because of its position in the electrochemical series? Options:
  A) Copper
  B) Iron
  C) Lead
  D) Potassium
  E) Zinc
  Show Answer
  The correct answer is D .
• Question 162:

  What is the state of matter in which particles are widely spaced and move freely with high kinetic energy?

  Options:
  A) Liquid
  B) Solid
  C) Plasma
  D) Gas
  Show Answer
  The correct answer is D .
• Question 163: How many unpaired electron are in the p-orbitals of a fluorine atom? Options:
  A) 3
  B) $0$
  C) 1
  D) 2
  Show Answer
  The correct answer is C .
• Question 164: What is the concentration of H⁺ ions in moles per dm³ of a sodium of pH 4.398? Options:
  A) 4.0 χ 10^-5
  B) 0.4 χ 10^-5
  C) 4.0 χ 10^-3
  D) 0.4 χ 10^-3
  Show Answer
  The correct answer is A .
• Question 165: When sodium ethanoate is treated with a few drops of concentrated tetraoxosulphate(vi)acid. one of the products is Options:
  A) CH₃COOH
  B) CH₃COOCH₃
  C) CH₃COOC₂H₅
  D) C₂H₅COOCH₃
  Show Answer
  The correct answer is A .
• Question 166:

  

  In the diagram above. X is

  Options:
  A) SO₃
  B) SO₂
  C) S
  D) H₂S
  Show Answer
  The correct answer is B .
• Question 167:

  Electrons enter into orbitals in order of increasing energy as exemplified by?

  Options:
  A) 1S${}^2$2S${}^2$2PX${}^2$2py${}^2$2pz${}^0$3s${}^0$
  B) 1S${}^2$2S${}^2$2PX${}^2$2py${}^1$2pz${}^1$3s${}^0$
  C) 1S${}^2$2S${}^2$2PX${}^1$2py${}^1$2pz${}^1$3s${}^1$
  D) 1S${}^2$2S${}^2$2PX${}^2$2py${}^2$2pz${}^0$3s${}^1$
  Show Answer
  The correct answer is B .
• Question 168: When chlorine Is passed into water and the resulting solution exposed to sunlight, the product formed are Options:
  A) Chlorine gas and hydrogen
  B) Oxygen and oxochlorate (I) acid
  C) Chlorine gas and oxochlorate (I) acid
  D) Hydrochloric acid and oxygen
  Show Answer
  The correct answer is D .
• Question 169: The atom of an element X is represented as _z^yX. The basic chemical properties of X depends on the value of Options:
  A) Y
  B) Z
  C) Y - Z
  D) Z - Y
  Show Answer
  The correct answer is B .
• Question 170: For iron to rust, there should be present? Options:
  A) oxygen
  B) moisture
  C) carbondioxide
  D) oxygen and moisture
  E) oxygen, moisture and carbondioxide
  Show Answer
  The correct answer is D .