The formula for molality is 
Given: A solution's molality equals 2.25 m
The weight of the solvent is 30 g, which is the same as 0.030 kg
Molecular weight of AlCl3 is 133.34 g/mol
Thus, we have the equation, 2.25 =
Therefore, the weight of the solute (g) becomes 9.00 g
Hence, <span>9.00 g of AlCl3 is necessary for creating a 2.25m solution in 30.0 g of water</span>
Given: A solution's molality equals 2.25 m
The weight of the solvent is 30 g, which is the same as 0.030 kg
Molecular weight of AlCl3 is 133.34 g/mol
Thus, we have the equation, 2.25 =
Therefore, the weight of the solute (g) becomes 9.00 g
Hence, <span>9.00 g of AlCl3 is necessary for creating a 2.25m solution in 30.0 g of water</span>