1. Calculate the moles of MgCl₂:
* Molar mass of MgCl₂:
* Mg: 24.31 g/mol
* Cl: 35.45 g/mol (x 2 for two chlorine atoms)
* Total: 24.31 + (35.45 x 2) = 95.21 g/mol
* Moles of MgCl₂:
* moles = mass / molar mass
* moles = 0.73 g / 95.21 g/mol
* moles ≈ 0.00767 mol
2. Convert volume to liters:
* Volume: 300 mL
* Liters: 300 mL / 1000 mL/L = 0.3 L
3. Calculate molarity:
* Molarity (M) = moles of solute / liters of solution
* Molarity = 0.00767 mol / 0.3 L
* Molarity ≈ 0.0256 M
Therefore, the molarity of the 0.73 g MgCl₂ solution in 300 mL is approximately 0.0256 M.
