Morality of sodium chloride
What is the molarity of a solution that contains 5.0 grams of sodium chloride (NaCl) dissolved in enough water to make a final volume of 250 mL?
SOLUTION:
1. Calculate the molar mass of NaCl:
Sodium (Na): 22.99 g/mol
Chlorine (Cl): 35.45 g/mol
Molar mass of NaCl = 22.99 + 35.45 = 58.44 g/mol
2. Calculate the number of moles of NaCl:
Moles of NaCl = mass (g) / molar mass (g/mol)
Moles of NaCl = 5.0 g / 58.44 g/mol 0.0857 moles
3. Convert the volume from mL to L:
250 mL = 0.250 L
4. Calculate the molarity (M):
Molarity (M) = moles of solute / volume of solution (L)
Molarity = 0.0857 moles / 0.250 L = 0.3428 M
Final Answer:
The molarity of the sodium chloride solution is approximately 0.34 M.
Your calculations are correct. The molarity of the solution is 0.3428 M.
Here's a breakdown of the steps you took:
- Calculated the molar mass of NaCl: You correctly added the atomic masses of sodium and chlorine to determine the molar mass of NaCl.
- Calculated the number of moles of NaCl: You divided the mass of NaCl by its molar mass to find the number of moles.
- Converted the volume from mL to L: You correctly converted the volume from milliliters to liters.
- Calculated the molarity: You correctly divided the number of moles of NaCl by the volume of the solution to calculate the molarity