What is the molality concentration when 0.14 moles of MgBr2 are dissolved in 12.75 moles of water?

A particular solute is dissolved in a solvent resulting in a solution that is 54.0 % solute by mass. If the molar mass of the solute is 178.10 g/mol, what is the molality of the solution? (Assume the solute is a nonelectrolyte).

What mass of H2O is needed to dissolve 4.69 g KMnO4 to produce a solution having a molality of 0.299 m? Assume that the density of the solution is 1.00 g/mL. The molar mass of KMnO4 is 158.03 g/mol and the molar mass of H2O is 18.02 g/mol.

A solution is prepared by dissolving 11.622 g sulfuric acid, H2SO4, (Molar Mass = 98.07848 ) in enough water to make 100.0 mL of solution. If the density of the solution is 1.115 g/mL, what is the molality? Report your answer using three decimal places.