Answer:
You first need to construct a balanced chemical equation to describe the reaction:
KOH + HNO3 ---------> KNO3 + H2O
Work out the no. moles of HNO3 being neutralized:
Moles = Volume x Concentration = (25/1000) x 0.0150 = 0.000375 moles
From the balanced equation the molar ratio of KOH to HNO3 is 1:1 so you also need 0.000375 moles of KOH to neutralise the nitric acid
Now you can work out the volume of KOH required:
Volume = Moles/Concentration = (0.000375)/0.05 = 0.0075 dm^3 = 7.5 cm^3
