passwella.
Menu

JAMB Chemistry 2009 Question 4

Question 4

Mole Concept and Stoichiometry

0.0075 mole of calcium trioxocarbonate(IV) is added to 0.015 mole of a solution of hydrochloric acid. The volume of gas evolved at s.t.p. is [Molar volume of a gas at s.t.p. = 22.4 dm3]

  1. A.224 cm3
  2. B.168 cm3
  3. C.112 cm3
  4. D.100 cm3
Show the answer and explanation

Answer: B (168 cm3)

Explanation

CaCO3 + 2HCl → CaCl2 + H2O + CO2. 0.0075 mol CaCO3 uses exactly 0.015 mol HCl and gives 0.0075 mol CO2 = 0.0075 × 22 400 = 168 cm3.