Answer:(3.66 /0.393= 9.3 ML of Ba(OH)2
Explanation: The original volume of the Ba(OH)2 solution is calculated as follows find the moles of HNO3 used
Ba(OH)2 + 2HNO3 =Ba(NO3)2 +2H2O
calculate the moles of HNO3 used =molarity x volume
= 32.24 x0.227= 7.32 moles
by use of mole ratio between Ba(OH)2 to HNO3 which is 1:2 the moles of Ba(OH)2 is, therefore, = 7.32 x1/2 =3.66 moles
volume of Ba(OH)2 is therefore = (3.66 /0.393= 9.3 ML of Ba(OH)2