1. Calculate the moles of NaOH:
* Molar mass of NaOH: 40 g/mol
* Moles of NaOH: (3.76 g) / (40 g/mol) = 0.094 mol
2. Calculate the volume of the solution in liters:
* Volume of water: 361 mL
* Volume of solution (approximately): 361 mL (since the volume of NaOH is negligible compared to the water)
* Volume in liters: 361 mL / 1000 mL/L = 0.361 L
3. Calculate the concentration of the NaOH solution:
* Concentration (Molarity): (Moles of NaOH) / (Volume of solution in liters)
* Concentration: (0.094 mol) / (0.361 L) = 0.260 M
Important Note: The information about the 491 HCl is not relevant to calculating the concentration of the original NaOH solution. Titration is a technique to determine the concentration of an unknown solution using a solution of known concentration, but the provided information about the HCl is not sufficient to do that.
