If Na has a mass of 23, and Cl a mass of 35, how many grams of NaCl are added to water to make one liter of a 3M solution?

Answer 1

Do you mean 3M NaCl?
molar mass NaCl = 35+23 = 58.
So you want 3 moles/L to make 3M.
Three (3) moles NaCl = 3 x 58 = ??g NaCl.

Answer 2

yes