Chemistry – Stoichiometry - The mole and the Avogadro constant | e-Consult

1. Calculate the molar mass of NaCl:

Molar mass of Na = 23 g/mol, Molar mass of Cl = 35.5 g/mol. Molar mass of NaCl = 23 + 35.5 = 58.5 g/mol

2. Calculate the number of moles of NaCl:

moles of NaCl = mass / molar mass = 10.0 g / 58.5 g/mol = 0.171 mol

3. Convert the volume of the solution to dm³:

250 cm³ = 0.250 dm³

4. Calculate the concentration in g/dm³:

Concentration (g/dm³) = mass / volume = 10.0 g / 0.250 dm³ = 40.0 g/dm³

5. Calculate the concentration in mol/dm³:

Concentration (mol/dm³) = moles / volume = 0.171 mol / 0.250 dm³ = 0.684 mol/dm³

Answer: The concentration of the sodium chloride solution is 40.0 g/dm³ and 0.684 mol/dm³.