Answer:
The percent by mass of nitric acid in the mixture is 5.48 %
Explanation:
Givn that
Mass of HNO3 = 9.03 grams
Volume of KOH = 12.0 mL = 0. 012 L
Molarity of KOH = 0.655 M
The balanced equation
Ba(OH)2 + HNO3 → Ba(NO3)2 + H2O
Calculate the moles of KOH
Moles of Ba(OH)2 = molarity KOH * volume
Moles Ba(OH)2 = 0.655 M * 0.012 L
Moles Ba(OH)2 = 0.00786 moles
Calculate moles of HNO3
For 1 mol of Ba(OH)2 we need 1 mol of HNO3
For 0.00786 moles of Ba(OH)2 we need 0.00786 moles of HNO3
Calculate mass of HNO3
Mass HNO3 = moles HNO3 * molar mass HNO3
Mass HNO3 = 0.00786 moles * 63.01 g/mol
Mass HNO3 = 0.495 grams
Calculate mass % HNO3 in sample
mass % = (0.495 grams / 9.03 grams)*100%
mass % = 5.48 %
The percent by mass of nitric acid in the mixture is 5.48 %