Answer:
80 ml.
Step-by-step explanation:
The balanced equation is:
KOH + HNO3 ----> KNO3 + H2O
So 1 mole of KOH reacts with 1 mole of HNO3
200ml of 0.16M KOH contains 0.16 * 200/1000
= 0.16 * 0.2
= 0.032 M KOH.
So we need the volume (V) of 0.4 M HNO3 which contains 0.032 moles.
0.4 * V = 0.032
V = 0.032 / 0.4
V = 0.08 liters
= 80 mls.