Answer:
150.0 mL.
Step-by-step explanation:
- It is known that the no. of millimoles of HNO₃ before dilution = the no. of millimoles of HNO₃ after dilution.
∵ (MV) before dilution = (MV) after dilution.
∴ V before dilution = (MV) after dilution / M before dilution = (0.15 M)(500.0 mL)/(0.50 M) = 150.0 mL.