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 1191: The type of bonding in {Cu(NH₃)₄}²⁺ is Options:
  A) coordinate
  B) electrovalent
  C) metallic
  D) covalent
  Show Answer
  The correct answer is A .
• Question 1192:

  The enzyme that converts glucose to ethylalcohol is?

  Options:
  A) maltase
  B) zymase
  C) Diatase
  D) Invertase
  Show Answer
  The correct answer is B .
• Question 1193:

  Which element is placed at the top of the electrochemicalseries?

  Options:
  A) Copper
  B) Hydrogen
  C) Sodium
  D) Oxygen
  Show Answer
  The correct answer is C .
• Question 1194:

  

  In the above set up substances X and Y are respectively

  Options:
  A) lime water copper (ll) tetraoxosulphate (lV)
  B) potassium trioxocarbonate and alkaline pyrogallol
  C) potassium hydroxide and alkaline pyrogallol
  D) potassium trioxocarbonate (lV) and concentrated tetraoxosulphate (IV) acid
  Show Answer
  The correct answer is C .
• Question 1195: The decolourization of purple colour of tetraoxomanganate (VII) ion is a test for Options:
  A) alkenes
  B) alkanols
  C) alkanals
  D) alkanes
  Show Answer
  The correct answer is A .
• Question 1196: If an element X of an atomic number Z and mass number Y is irradiated by an intense concentration of neutrons, the relevant nuclear equation is? Options:
  A) ^y_zX + ¹₀n → ^{y - 1}_{z + 1}X
  B) ^y_zX + ¹₀n → ^{y + 1}_zX
  C) ^y_zX + ¹₀n → ^y_{z + 1}X
  D) ^y_zX + ¹₀n → ^{y + 1}_{z - 1}X
  Show Answer
  The correct answer is B .
• Question 1197: The removal of rust from iron by treatment with tetraoxosulphate (IV) acid is based on the? Options:
  A) hydrolysis of the iron
  B) reaction of acid with base
  C) oxidationof the rust
  D) dehydration of the iron
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  The correct answer is D .
• Question 1198: MnO_4(aq) + 8H + _(aq) + 5Fe²⁺ → Mn^2+(aq) + 4H₂O_(I). The oxidation number of manganese in the above reaction changed from? Options:
  A) +7 to +2
  B) +6 to +2
  C) +5 to +2
  D) +4 to +2
  Show Answer
  The correct answer is A .
• Question 1199: Which of the following is found in cotton Options:
  A) Starch
  B) Cellulose
  C) Fat
  D) Oil
  Show Answer
  The correct answer is B .
• Question 1200: Ca(OH)_2(s) + 2NH₄Cl_(g) → CaCl_2(s) + 2H₂O_2(l) + X. In the reaction above X is Options:
  A) NO₂
  B) NH₃
  C) N₂O
  D) NO₂
  Show Answer
  The correct answer is B .