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JAMB Chemistry 1999 Question 7

Question 7

Mole Concept and Stoichiometry

Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g). From the equation above, the mass of magnesium required to react with 250 cm3 of 0.5 M HCl is [Mg = 24].

  1. A.0.3 g
  2. B.1.5 g
  3. C.2.4 g
  4. D.3.0 g
Show the answer and explanation

Answer: B (1.5 g)

Explanation

HCl = 0.25 × 0.5 = 0.125 mol. Mg needed = 0.125/2 = 0.0625 mol = 0.0625 × 24 = 1.5 g.