A standard solution of Ba(OH)₂ (concentration 0.25 mol dm^-3) was added to 50 cm³ of a HNO₃ solution, concentration unknown. On addition of 28.35 cm³ Ba(OH)₂, the equivalence point was reached. What is the concentration (in mol dm^-3) of the sodium hydroxide solution? Ba(OH)₂ (aq) + 2 HNO₃ (aq) → Ba(NO₃)₂ (aq) + 2 H₂O (l)

Question

Quizplus · Accepted Answer

The balanced equation shows that 1 mole of Ba(OH)₂ reacts with 2 moles of HNO₃. The moles of Ba(OH)₂ used are 0.25 mol/dm³ × 28.35 cm³ × (1 dm³/1000 cm³) = 0.0070875 mol. Therefore, the moles of HNO₃ are 2 × 0.0070875 mol = 0.014175 mol. The concentration of HNO₃ is 0.014175 mol / 0.050 dm³ = 0.2835 mol/dm³, which rounds to 0.28 mol/dm³.

A Standard Solution of Ba(OH)2 (Concentration 0

A Standard Solution of Ba(OH)₂ (Concentration 0