A 0.110 L sample of an unknown HNO3 solution required 35.3 mL of 0.100 M Ba(OH)2 for complete neutralization. What is the concentration of the HNO3 solution?

Answer 1

Write the balanced equation

2HNO3 + Ba(OH)2 ==> Ba(NO3)2 + 2H2O

Find moles Ba(OH)2 used: 35.3 ml x 1L/1000 ml x 0.100 mol/L = 0.00353 moles

Find moles HNO3 present = 0.00353 mols Ba(OH)2 x 2 mol HNO3/mol Ba(OH)2 = 0.00706 mol

Calculate concentration of HNO3: 0.00706 mol / 0.110 L = 0.0642 M