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 1111: Calculate the volume of carbon (IV)oxide measured at s.t.p, produced when 1 kg of potassium hydrogen trioxocarbonate (IV) is totally decomposed by heat?(G.M.V. at s.t.p 22.4 dm³, K = 39, O = 16, C = 12, H = 1) Options:
  A) 28 dm³
  B) 56 dm³
  C) 112 dm³
  D) 196 dm³
  Show Answer
  The correct answer is C .
• Question 1112: Sieving is a technique used to separate mixture containing solid particles of Options:
  A) small sizes
  B) large sizes
  C) differents sizes
  D) the same sizes
  Show Answer
  The correct answer is C .
• Question 1113: In the periodic table, the electrical and thermal conductivities are properties of elements that Options:
  A) decrease across the period and increase down the group
  B) increase across the period and decrease down the group
  C) decrease across the period and down the group`
  D) increase acrosss the period and down the group
  Show Answer
  The correct answer is A .
• Question 1114: The exhaust fumes from a garage in a place that uses petrol of high sulphur content are bound to contain? Options:
  A) CO and SO₃
  B) CO and SO₂
  C) CO,SO₂ and SO₃
  D) CO and H₂S
  Show Answer
  The correct answer is B .
• Question 1115: The final products of the reaction between methane and chlorine in the presence of ultraviolet light are hydrogen chloride and Options:
  A) tricloromethane
  B) dichloromethane
  C) tetrachloromethane
  D) chloromethane
  Show Answer
  The correct answer is C .
• Question 1116:

  A given amount of gas occupies 10.0 dm³ at atm, and 273°C. The number of moles of the gas present is?

  (Molar volume of a gas at s.t.p. = 22.4 dm³)

  Options:
  A) 0.89 mol
  B) 1.90 mol
  C) 3.80 mol
  D) 5.70 mol
  Show Answer
  The correct answer is B .
• Question 1117: The thermal decomposition of copper (ll)trioxonitrate (V) yields copper (ll) oxide, oxygen and? Options:
  A) nitrogen (ll) oxide
  B) nitrogen (l) oxide
  C) nitrogen (lV) oxide
  D) nitrogen
  Show Answer
  The correct answer is C .
• Question 1118:

  

  Use the figure above to answer this question. Which of the following compounds is an isomer of the compound

  Options:
  A) A
  B) B
  C) C
  D) D
  Show Answer
  The correct answer is D .
• Question 1119: When excess ethanol is heated to 145 ^oC in the presence of concentrated sulphuric acid, the product is Options:
  A) diethyl ether
  B) ethyne
  C) diethyl sulphate
  D) acetone
  E) ethanoic acid
  Show Answer
  The correct answer is A .
• Question 1120: The compound produced when sodium peroxide is heated with excess sodium is Options:
  A) Na₂CO₃
  B) Na₂O
  C) NaNO₂
  D) NaOH
  Show Answer
  The correct answer is B .