2HNO3(aq)+Ba(OH)2(aq)⟶2H2O(l)+Ba(NO3)2(aq)A 0.115 L sample of an unknown HNO3 solution required 31.7 mL of 0.200 M Ba(OH)2 for complete neutralization. What is the concentration of the HNO3 solution?

Answer 1

2HNO₃(aq) + Ba(OH)₂(aq) ==> 2H₂O(l) + Ba(NO₃₎₂(aq) ... BALANCED EQUATION

moles of Ba(OH)₂ used for neutralization = 31.7 ml x 1 L/1000 ml x 0.200 mol/L = 0.00634 mol Ba(OH)₂

moles HNO₃ present = 0.00634 mol Ba(OH)₂ x 2 mol HNO₃/mol Ba(OH)₂ = 0.01268 mol HNO₃

[HNO₃]: (0.115 L)(x mol/L) = 0.01268 moles and x = 0.110 mol/L = 0.110 M HNO₃