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

Multiple Choice

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)

A) 0.014
B) 0.28
C) 0.25
D) 7.0875 × 10^-3