Answer:
[MgCl₂] = 1.05 m
Explanation:
Molality is a type of concentration that indicates the moles of solute in 1000g of solvent.
m = mol/kg.
Our solute is MgCl₂. We convert mass to moles:
25 g . 1mol / 95.21 g = 0.262 moles.
Our solvent is water → 250 mL of H₂O
We use density to determine the mass: density = m / V
Density . V = m → 0.9975 g/mL . 250 mL = 249.3 g
We convert from g to kg = 249.3 g . 1kg/1000g = 0.2493kg
molality → 0.262 mol /0.2493kg = 1.05
