Question

Consider the neutralization reaction below.

2HNO3(aq) + Ba(OH)2(aq) -> 2H2O(l) + Ba(NO3)2(aq)

A 0.110-L sample of an unknown HNO3 solution required 31.7 mL of 0.150 M Ba(OH)2 for complete neutralization. What was the concentration of the HNO3 solution?

? = M

Answer 1

molarity of Ba(OH)2 = number of moles of Ba(OH)2 / volume of solution in L

0.150 = number of moles of Ba(OH)2 / 0.0317 L

number of moles of Ba(OH)2 = 0.004755 mole

from the balanced equation we can say that

1 mole of Ba(OH)2 requires 2 mole of HNO3 so

0.004755 mole of Ba(OH)2 will require 0.00951 mole of HNO3

molarity of HNO3 = number of moles of HNO3 / volume of solution in L

molarity of HNO3 = 0.00951 mole / 0.110 = 0.0865 M

Therefore, the molarity of HNO3 = 0.0865 M