Textbook 6B.11

[Kyle_Phong_2J]

For this textbook question, there is initially 200 mL of solution and 5 mL of that is transferred elsewhere and diluted to 500 mL. How do you know what values to use for this dilution?

[HaleyWong1A]

For this one you are working backwards because you can determine the concentration of OH using the pH that they give you. From there that is the concentration in your final solution of 500 ml and you can use C1V1 = C2V2, your equation would be C1 (5mL) = C2 (which you found from the pH --> pOH --> [OH-]) x 500 ml. This would solve for the concentration of the initial (aka C1). You would use 500 ml as your final volume and 5 mL as your initial because that it the amount you took out of the original 200 ml and diluted into 500 mL