You are instructed to prepare 250 mL of a solution which is 50 M in NaCl and 0.10 M in acetic acid. Solid NaCl and a 3.0 M solution are avaliable. How would you prepare this solution?

Answer 1

Is that 50M NaCl or 0.50M NaCl?
How many mols NaCl do you need? That is M x L = ? Then mols = g/molar mass and solve for grams NaCl. Weigh out that much NaCl and add to a 250 mL volumetric flask.
How many mols acetic acid do you need? That is M x L = 0.1 x 0.250 = 0.025
You have 3M; how much do you need of that?
M = mols/L or L = mols/M = 0.025/0.1 = ?L and convert to mL.
Add the acetic acid and about 100 mL water, swirl until the NaCl has completely dissolved, then add water to the mark and mix thoroughly.