Around #58*g# is acceptable so long as it is accurately weighed; this is quantitatively transferred into a #1L# volumetric flask. Pour in distilled water and swirl until the solute is dissolved. Then carefully fill the flask up to the #1*L# graduation with more distilled water.
#"Concentration"# #=# #(58.4400*g)/(58.44*g*mol^-1)xx1/(1.000*L)# #=# #??mol*L^-1#.
If I had a #250*mL# volumetric flask, what mass of sodium chloride would I need in that instance?