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 1231:

  

  In the diagram above the gas Y could be

  Options:
  A) hydrogen chloride
  B) oxygen
  C) carbon (IV) oxide
  D) chlorine
  Show Answer
  The correct answer is A .
• Question 1232: By means of filtration, one component can be obtained pure from an aqueous mixture of sodium chloride and Options:
  A) potassium nitrate
  B) sand
  C) lead nitrate
  D) sugar (glucose)
  E) starch
  Show Answer
  The correct answer is B .
• Question 1233: 20 cm³ of a 2.0 M solution of ethanoic acid was added to excess of 0.05 M sodium hydroxide. The mass of the salt produced is?(Na = 23, C = 12, O = 16, H = 1) Options:
  A) 2.50 g
  B) 2.73 g
  C) 3.28 g
  D) 4.54 g
  Show Answer
  The correct answer is C .
• Question 1234: Which of the following statement is false? Options:
  A) Acids react with some metals, liberating hydrogen
  B) Acids react with carbonates, liberating carbondioxide
  C) Acids conduct electricity and are decomposed by the current, liberating hydrogen at the anode
  D) Acids have a sour taste
  E) Acids change the colour of indicators
  Show Answer
  The correct answer is C .
• Question 1235:

  8g of CH${}_4$ occupies 11.2 at S.T.P. What volume would 22g of CH${}_3$CH${}_2$CH${}_3$ occupy under the same condition?

  Options:
  A) 3.7dm${}^3$
  B) 11.2dm${}^3$
  C) 22.4dm${}^3$
  D) 33dm${}^3$
  Show Answer
  The correct answer is B .
• Question 1236:

  Which transition metal is known for its multiple colorful oxidation states and compounds used in pigments and paints?

  Options:
  A) Silver (Ag)
  B) Copper (Cu)
  C) Gold (Au)
  D) Zinc (Zn)
  Show Answer
  The correct answer is B .
• Question 1237: Using 50 cm ³ of 1 M potassium hydroxide and 100cm ³ of 1 M tetraoxosulphate (VI) acid, calculate the respective volumes in cm ³ of base and acid that would be required to produce the maximum amount of potassium tetraoxosulphate (IV) [ = 39, S = 32, O = 16, H = 1] Options:
  A) 50, 50
  B) 25, 50
  C) 50, 25
  D) 25, 25
  Show Answer
  The correct answer is D .
• Question 1238: What type of bond exits between an element X with atomic number 12 and Y with atomic number 17? Options:
  A) Electrovalent
  B) Metallic
  C) Covalent
  D) Dative
  Show Answer
  The correct answer is A .
• Question 1239:

  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 1240: The most volatile fraction obtained from fractional distillation of crude petroleum contains? Options:
  A) butane , propane and kerosene
  B) butane , propane and petrol
  C) ethane, methane and benzene
  D) methane, ethane and propane
  Show Answer
  The correct answer is D .