Prepare 250ml of a 4.8M NaCl solution.

First we need to calculate the number of moles of NaCl in 250 ml of 4.8 M NaCl solution.

Number of moles = molarity * (volume of solution in L)

= (4.8 M) * (250/1000 L) = 1.2 moles

Now calculte the mass of NaCl required to be dissolved in 250 ml to prepare 4.8 M Nacl solution.

Hence, mass of NaCl = moles of NaCl * molar mass of NaCl

= 1.2 moles*58.5 g/mol = 70. 2 g

Thus, we need nto dissolve 70.2 grams of NaCl in 50 ml water and then dilute it to 250 ml to get the moalrity of 4.8 M.