dilution

  1. If I have 340 mL of a 0.5 M NaBr solution, what will the concentration be if I add 560 mL more water to it?

\((340 mL)(0.5 M) = (900 mL)(x M)\)

\(x = \frac{340 * 0.5}{900}\)

\(x \approx 0.189 M\)

  1. If I dilute 250 mL of 0.10 M lithium acetate solution to a volume of 750 mL, what will the concentration of this solution be?

\((250 mL)(0.10 M) = (750 mL)(x M)\)

\(x = \frac{250*0.10}{750}\)

\(x \approx 0.03 M\)

  1. If I leave 750 mL of 0.50 M sodium chloride solution uncovered on a windowsill and 150 mL of the solvent evaporates, what will the new concentration of the sodium chloride solution be?

\((750 mL)(0.50 M) = (600 mL)(x M)\)

\(x = \frac{750*0.50}{600}\)

\(x = 0.625 M\)

  1. To what volume would I need to add water to the evaporated solution in problem 3 to get a solution with a concentration of 0.25 M?

\((600 mL)(0.625 M) = (x mL)(0.25 M)\)

\(x = \frac{600*0.625}{0.25}\)

\(x = 1500 mL\)

add 900mL

  1. Calculate the volume of a 17.5M stock solution of NaOH needed to prepare 200. mL of a 2.5M solution.

\((200 mL)(2.5M) = (xmL)(17.5)\)

\(x = \frac{200*2.5}{17.5}\)

\(x \approx 28.57 mL\)

add 171.43 ml water to soln to make 200 mL 2.5 M soln


Last update: June 5, 2023
Created: June 5, 2023