How do you prepare phosphate buffer solution of pH 6.8?

Answer 1

Phosphate buffer pH 6.8 preparation protocol below

Stock solutions:

0.2M dibasic sodium phosphate (1 liter)

Na2HPO4*12H2O (MW=358.14) --------71.64gm + dH2O to make 1 liter (Solution X)

0.2M monobasic sodium phosphate (1 liter)

NaH2PO4*H2O (MW=138.01) --------27.6gm + dH2O to make 1liter (Solution Y)

Working buffer: 0.1M (1 liter)

pH 6.8 245 ml solution X + 255 ml solution Y ( filled up to 1 liter with dH2O)

Answer 2

Try using this equation:

(F.W. with unit g/mol)(Molarity with unit mol/L)(vol. needed with unit L) = amt. reagent needed with unit g

After the potassium is measured and your solution is made (minus a small amount of water for pHing), check the pH. Adjust pH according. Que solution up to final volume.

Answer 3

First, you have to prepare Phosphate Buffer A by diluting 31.2 grams NaH2PO4*2H20 to 1000mL. Second, prepare Phosphate Buffer B by diluting 53.61 grams Na2HPO4*7H20 (You can also use Na2HPO4 or Na2HPO4*12H20, but the amount to be used is different, so you have to compute for it) to 1000mL. Then, mix 62.5% of Buffer A with 37.5% of Buffer B. Adjust the PH using NaOH and H2PO4.

Answer 4

Dissolve 90g of NaHPO4.H2O in 500 ml of water. After complete

dissolution add 32.7 g of dibasic phosphate (Na2HPO4, 99.5%) and stir the mixture until totally dissolved. You can verify the pH using a pH meter. Dilute NaOH or H3PO4 can be added to adjust the pH if necessary.

Answer 5

1. Make 0.3M K2HPO4 or Na2HPO4

2. Make 0.3M KH2PO4 or NAH2PO4

3. Carefully mix Sodium/Potassium mono- and dibasic- phosphate solutions so that pH is 6.0

Answer 6

This equation should work with the above measurements.

(F.W. with unit g/mol)(Molarity with unit mol/L)(vol. needed with unit L) = amt. reagent needed with unit g

Answer 7

100 mL 0,05 M KH2PO4 + 44,8 mL 0,05 NaOH