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 2101:

  Burning magnesium ribbon in air removes which of the following

  (i) oxygen (ii) nitrogen (iii) argon and (iv) carbon(iv)oxide?

  Options:
  A) i and iv only
  B) i, ii, iii and iv only
  C) i only
  D) i and ii only
  Show Answer
  The correct answer is C .
• Question 2102: If glucose is heated with concentration tetraoxosulphate (VI) acid, it will be dehydrated to Options:
  A) carbon
  B) carbon (IV) oxide
  C) ethene
  D) ethanol
  Show Answer
  The correct answer is A .
• Question 2103: The gas that is removed by the water in the flask is Options:
  A) O ₂
  B) SO ₂
  C) HCI
  D) H ₂
  Show Answer
  The correct answer is C .
• Question 2104:

  I. Treatment of cancerII. Detection of leakages in water mainsIII. Detection of the ages of ancient toolsIV. Preparation of drugs

  Which combination of the above refers to the uses of radioactive isotopes?

  Options:
  A) I and III
  B) I and II
  C) I, II and III
  D) I, II, III and IV
  Show Answer
  The correct answer is C .
• Question 2105:

  Chlorine, consisting of two isotopes of mass numbers 35 and 37, has an atomic mass of 35.5.

  The relative abundance of the isotope of mass number 37 is?

  Options:
  A) 20
  B) 25
  C) 50
  D) 75
  Show Answer
  The correct answer is B .
• Question 2106:

  In the reactions

  (I) H₂ (g) + 1/2O₂(g) → H₂O(l); ∆H = -286 KJ

  (II) C(s) + O₂g) → CO₂ (g); ∆H = -406 KJ the equations imply that

  Options:
  A) more heat is absorbed in (l)
  B) more heat is absorbed in (ll)
  C) less heat is evolved in (l)
  D) reaction (ll) proceeds faster than (l)
  E) reaction (l) proceeds faster than (ll)
  Show Answer
  The correct answer is C .
• Question 2107:

  CH_4(g) + CI_2(g) $\to$ CH₂CI_(s) + HCI_g

  The major factor that influences the rate of the reaction above is

  Options:
  A) Concentration
  B) Catalyst
  C) Temperature
  D) Light
  Show Answer
  The correct answer is D .
• Question 2108:

  

  The compound above exhibits

  Options:
  A) geometric isomerism
  B) optical isomerism
  C) structural isomerism
  D) positional isomerism
  Show Answer
  The correct answer is B .
• Question 2109: How many faraday of electricity is required to produce 0.25 mole of copper? Options:
  A) 1.00F
  B) 0.01F
  C) 0.05F
  D) 0.50F
  Show Answer
  The correct answer is D .
• Question 2110: The salt formed from a weak acid and a strong base hydrolyzes in water to form Options:
  A) A saturated solution
  B) an acidic solution
  C) a buffer solution
  D) an alkaline solution
  Show Answer
  The correct answer is D .