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JAMB Chemistry 2004 Question 4

Question 4

Mole Concept and Stoichiometry

What volume of gas is evolved at s.t.p. if 2g of calcium trioxocarbonate (IV) is added to a solution of hydrochloric acid? [Ca = 40, C = 12, O = 16, Cl = 35.5, H = 1, Molar volume of a gas at s.t.p. = 22.4dm3]

  1. A.112cm3
  2. B.224cm3
  3. C.448cm3
  4. D.2240cm3
Show the answer and explanation

Answer: C (448cm3)

Explanation

CaCO3 (100 g/mol) gives one mole of CO2 per mole. 2 g = 0.02 mol, so CO2 = 0.02 × 22 400 = 448 cm3.