1. Convert milligrams of NaCl to grams:

* 147 mg NaCl * (1 g / 1000 mg) = 0.147 g NaCl

2. Calculate the moles of NaCl:

* Moles = mass / molar mass

* Molar mass of NaCl = 58.44 g/mol

* Moles of NaCl = 0.147 g / 58.44 g/mol = 0.00251 mol NaCl

3. Use the molarity to find the volume:

* Molarity (M) = moles / volume (L)

* Volume (L) = moles / molarity

* Volume (L) = 0.00251 mol / 1.38 mol/L = 0.00182 L

4. Convert liters to milliliters:

* 0.00182 L * (1000 mL / 1 L) = 1.82 mL

Therefore, you would need 1.82 mL of the 1.38 M NaCl solution to contain 147 mg of NaCl.