Find the mass in grams of aluminum nitrate, al(no3)3, required to mix with 750 g of water to makea 1.5m solution.

            Mass  =  239.62 g

Explanation:

Molality is given as,

                               m  =  Moles of Solute / Kg of Solvent   ---  (1)

Data Given;
                   Molality  =  1.5 m

                   Mass of Solvent  =  750 g  =  0.75 Kg

Solving eq. 1 for Moles,

                          Moles  =  Molality × Mass of Solvent

Putting values,
                          Moles  =  1.5 mol.Kg⁻¹ × 0.75 Kg

                          Moles  =  1.125 mol

Calculating mass from moles,

                          Moles  =  Mass / M.mass
Or,
                          Mass  =  Moles × M.mass

Putting values,
                          Mass  =  1.125 mol × 213 g.mol⁻¹

                          Mass  =  239.62 g

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.

Density and pressure