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 221: When stem is passed over red hot carbon the substances produced are Options:
  A) hydrogen and trioxocarbonate (IV) acid
  B) hydrogen, oxygen and carbon (IV) oxide
  C) hydrogen and carbon (ii) oxide
  D) hydrogen and carbon (IV) oxide
  Show Answer
  The correct answer is C .
• Question 222:

  When dilute aqueous solutions of lead (II) nitrate and potassium bromide are mixed, a precipitate is observed.

  The products of this reaction are?

  Options:
  A) PbO_(s) + Br^- + KNO₃
  B) Br₂ + NO_2(g) + PbBr_2(s)
  C) PbO_(s) + K⁺_(aq) + Br_(aq) + NO_2(g)
  D) PbBr_2(s) + K_(aq) + K⁺_(aq) + NO_3(aq)
  Show Answer
  The correct answer is D .
• Question 223:

  If acidified Potassium Dichromate(VI) (K${}_2$Cr${}_2$O${}_7$) acts as oxidizing agent, color changes from

  Options:
  A) yellow to green
  B) orange to green
  C) yellow to red
  D) orange to red
  Show Answer
  The correct answer is B .
• Question 224: 0.1 Faraday of electricity was passed through a solution of copper (ll) sulphate. The maximum weight of copper deposited on the cathode would be [Cu = 64] Options:
  A) 64.0g
  B) 32.0g
  C) 16.0g
  D) 6.4 g
  E) 3.2g
  Show Answer
  The correct answer is E .
• Question 225: When sulphur (IV) oxide is passed into a solution of sodium hydroxide for a long time, it eventually produces a solution of Options:
  A) NaHSO₄
  B) Na₂SO₃
  C) NaHSO₃
  D) Na₂SO₄
  Show Answer
  The correct answer is B .
• Question 226:

  What is the PH of 0.00 1 moldm${}^3$ solution of the sodium hydroxide

  Options:
  A) 14
  B) 13
  C) 12
  D) 11
  Show Answer
  The correct answer is D .
• Question 227: Which of the following CANNOT be obtained by fractional distillation of petroleum? Options:
  A) Ether
  B) Methane
  C) Butane
  D) Ethene
  E) Hydrogen
  Show Answer
  The correct answer is E .
• Question 228:

  Which of the following is a common laboratory indicator for bases?

  Options:
  A) Methyl orange
  B) Phenolphthalein
  C) Bromothymol blue
  D) Litmus
  Show Answer
  The correct answer is B .
• Question 229: 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 230:

  

  The IUPAC name for the compound is

  Options:
  A) 2,3-dimethylpent-2,3-ene
  B) 2, 3- dimethylpent-2-ene
  C) 3, 4-dimethylpent-3-ene
  D) 3,4-dimethylpentene
  E) 3,4-dimethlhept-2-ene
  Show Answer
  The correct answer is B .