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JAMB Chemistry 1997 Question 20

Question 20

Volumetric Analysis

Given that 15.00 cm3 of H2SO4 was required to completely neutralize 25.00 cm3 of 0.125 mol dm−3 NaOH, calculate the molar concentration of the acid solution:

  1. A.0.925 mol dm−3
  2. B.0.156 mol dm−3
  3. C.0.104 mol dm−3
  4. D.0.023 mol dm−3.
Show the answer and explanation

Answer: C (0.104 mol dm−3)

Explanation

H2SO4 + 2NaOH → Na2SO4 + 2H2O. Moles NaOH = 0.025 × 0.125 = 0.003125, so acid = 0.0015625 mol in 0.015 dm3 = 0.104 mol dm−3.