Here's how to calculate the volume of solution needed:

Understanding Molarity

Molarity (M) is a measure of concentration defined as moles of solute per liter of solution:

* M = moles of solute / liters of solution

Solving for Volume

1. Rearrange the equation: We need to find the volume (liters of solution), so rearrange the equation:

* Liters of solution = moles of solute / Molarity

2. Plug in the values:

* Liters of solution = 0.25 moles NaCl / 3.0 M

3. Calculate:

* Liters of solution = 0.0833 L

Convert to Milliliters (optional)

* Since 1 L = 1000 mL, the volume in milliliters is:

* 0.0833 L * 1000 mL/L = 83.3 mL

Answer: You would need 83.3 mL of solution to dissolve 0.25 moles of NaCl to make a 3.0 M solution.