Exercises

1. How would you prepare 500.0 mL of 0.050 M phosphate buffer solution, pH 6.7 from

0.20 M solutions of acid and salt?

First, I would calculate the mass of the acid and its salt needed. Below is how I

calculated it.

Next, I would weigh the calculated acid and salt then dissolve it in 250mL of

distilled H2O in a beaker. Once both are fully dissolved, I would use a pH meter

to obtain the pH of the solution. I would then adjust it with either a strong base or

acid if I do not attain the pH level I desire. After, I would transfer the solution to a

volumetric flask then dilute to mark. Lastly, I will transfer it to an Erlenmeyer

flask and cover it with a stopper.

2. What will be resulting pH of the buffer in Question # 1 if the following are added:

a. 1.0 mL of 1.0 M HCl

Buffers Exercises

organic- bio chemistry (CHEM153L)