ow much of the 0.2M stock solution of NaCl did you need to make a 100mL dilution of NaCl at final concentration 0.05M? Please give your answer in units of MILLILITERS, however do not explicitly include any units in your answer.

You would need 25 mL of the 0.2M stock solution of NaCl to make a 100mL dilution at a final concentration of 0.05M.