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.
