8/8/2019 Buffer Solution Challenge

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Buffer Capacity and Preparation of Isotonic Buffered Preserved

Solution

Solve this problemAt a hydrogen ion concentration of 1.75 * 10-5 (pH = 4.76), what is the capacity of

buffer containing 0.20 mole of each of acetic acid and sodium acetate per liter of

solution if0.01 M NaoH is added?

Preparation of isotonic buffered preserved solution:a. Prepare a 100 ml of Sorensen Phosphate buffered isotonic solutions, using

table#1.

Monobasic sodium phosphate solution = 8.00 g / 1000 ml

Dibasic sodium phosphate solution = 9.47 g / 1000 ml.

b. Add Chlorobutanol 0.7% as a preservative. Do the required calculation beforeits addition. (V-value of 0.3 g of Chlorobutanol is 8 ml)N.B. calculate the required amount of the chemicals in step (a) and (b).

Monobasic

Sodium Phosphate

Solution mL

Dibasic S.P.S.

mL

Resulting

buffer solution

pH mL

NaCl to render

isotonic g

90 10 5.9 0.52

80 20 6.2 0.51

70 30 6.5 0.50

60 40 6.6 0.49

50 50 6.8 0.48

40 60 7.0 0.46

30 70 7.2 0.45

20 80 7.4 0.44

10 90 7.7 0.43

5 95 8.0 0.42

Table # 1:Sorensen Phosphate Buffer Solution

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