Understanding the Concepts

* Molality (m): Molality is a measure of concentration defined as moles of solute per kilogram of solvent.

* Volume: The volume of the solution is given in milliliters (mL).

Steps to Solve

1. Convert volume to kilograms:

* Since molality uses kilograms of solvent, we need to convert the volume from mL to kg. We'll need the density of the solution (which isn't given). Let's assume a density close to that of water (1 g/mL).

* 50.0 mL * (1 g/mL) = 50.0 g

* 50.0 g * (1 kg/1000 g) = 0.050 kg

2. Calculate moles of NaCl:

* We know the molality (2.15 m) means there are 2.15 moles of NaCl per kilogram of solvent.

* Since we have 0.050 kg of solvent, we can find the moles of NaCl:

* 2.15 mol/kg * 0.050 kg = 0.1075 moles NaCl

Therefore, there are approximately 0.1075 moles of sodium chloride present in the solution.

Important Note: This calculation assumes the density of the solution is close to that of water. If you have the actual density of the solution, you can get a more accurate result.