Asolution was prepared by dissolving 40.0 g of kcl in 225 g of water. part a calculate the mass percent of kcl in the solution. express your answer with the appropriate units. 15.1 {\rm \\%} calculate the mole fraction of the ionic species kcl in the solution.

Explanation:

(a)   According to the given data, mass of the solution will be calculated as follows.

          Mass of solution = Mass of KCl + Mass of water

                                      = (40 + 225) g

                                      = 265 g

Therefore, (m/m)% of KCl will be calculated as follows.

           (m/m)% of KCl =    

                                   =

                                   = 15.09%

Hence, mass percent of KCl in the solution is 15.09%.

(b)    Now, we will calculate the mole fraction of ionic species present in KCl  in the solution are follows.

Molar mass of KCl is 74.55 g/mol.

                Moles of KCl =

                                      =

                                      = 0.536 mol

or,                                   = 0.54 mol

As, molar mass of water is 18 g/mol. Hence, moles of water will be calculated as follows.

           Moles of =

                                      =

                                      = 12.5 mol

So, total number of moles = moles of KCl + moles of

                                           = (0.54 + 12.5) mol

                                           = 13.04 mol

Calculate the mole fraction of KCl in the solution as follows.

              Mole fraction =

                                     =

                                     = 0.041

Therefore, mole fraction of the ionic species KCl in the solution is 0.041.