Question

A student is asked to make 500 mL of a buffer solution for an upcoming laboratory investigation that requires 50.0 mL of 3.0 M phosphoric acid. The student searches the acid cabinet in the stockroom but can only find 4.5 M phosphoric acid. Calculate the amount of 4.5 M phosphoric acid the student should dilute to a total volume of 500 mL. Give our answer to the nearest tenth of a mL.

Answer 1

To solve this we use the equation,

M1V1 = M2V2

where M1 is the concentration of the stock solution, V1 is the volume of the stock solution, M2 is the concentration of the new solution and V2 is its volume.

4.5 ( V1 ) = 3.0 ( 500 mL )

V1 = 333.33 mL needed of the 4.5 M phosphoric acid

Hope this answers the question. Have a nice day.