Question

Calculate the molality of a dextrose (mw = 180.16 g/mole) solution prepared by dissolving 52.8 g dextrose in 500 mL of water (density of the solution is 1.06).

Answer 1

Molalily = moles of substance x1000/weight of solvent in gm

moles of substance = weight/molecular weight

                                   = 52.8/180.16

                                   = 0.293

now weight of solvent w = ?

density of water is 1.06

d = M/V

D = w.t x V/M.w

now Wt = 476 g

now molality = 0.293 x 1000/476

                       = 0.615