Question

1- Calculate the osmolar concentration, in terms of milliosmoles, represented by 1 liter of a 10% w/v solution of anhydrous dextrose (Z = 180) in water. Answer: 555.56 mOsmol/L

Answer 1

10 % w/v dextrose solution means

10 g of the dextrose contained in 100 mL of solution

10x10= 100 g of dextrose contained in 100x10 = 1000 mL = 1L of solution

So number of moles of dextrose solution , n = mass / molar mass

                                                                 = 100g / 180(g/mol)

                                                                 = 555.56x10^-3 moles

                                                                 = 555.56 mmoles

So concentration of dextrose solution is moles / volume in L

                                                         = 555.56 mOsmoles/L