Answer: 2.5 ml of 0.5 M HNO3 is necessary to titrate 25.0 mL of 0.05 M KOH
solution to the endpoint
Step-by-step explanation:
To calculate the volume of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is

are the n-factor, molarity and volume of base which is KOH.
We are given:

Putting values in above equation, we get:

Thus 2.5 ml of 0.5 M HNO3 is necessary to titrate 25.0 mL of 0.05 M KOH
solution to the endpoint