Answer:
Freezing point of solution = - 2.82°C
Explanation:
Formula to solve this, if we assume complete ionization of salt.
AlNO₃ → Al³⁺ + 3NO⁻ i = 4
Freezing point of solution = - (Kf. m . i - 0°C)
Freezing point of pure solvent - Freezing point of solution = Kf . m . i
Freezing point of pure solvent = 0°C
Kf for water = 1.86 °C / m
Let's convert the mass of solute to moles → 287 g . 1mol/ 88.98 g = 3.22 moles
m (mol/kg) → 3.22 moles / 8.50 kg = 0.379
Freezing point of solution = - Kf. m . i + 0°C
Freezing point of solution = - 1.86°C /m . 0.379 m . 4 → - 2.82°C
