Читать книгу Food Chemistry - Dennis D. Miller - Страница 27

1 pH = 3.7; pKa = 5.4.

2 14.68 g sodium acetate; 19.26 g acetic acid.

3 Use NaOH to adjust pH; dissolve 6 g NaH2PO4 (or 6.9 g NaH2PO4·H2O) in water (~900 ml); using pH meter, titrate to pH 7.0 with 1.0 N NaOH; transfer to a volumetric flask and dilute to 1 l.

4 a)pH 5.2 acetate buffer: mix 768 ml 0.1 M sodium acetate and 232 ml acetic acid. pH 7.6 phosphate buffer: mix 128 ml 1/15 M KH2PO4 and 872 ml 1/15 M Na2HPO4.b)Calculated pHs: Acetate buffer = 5.27; Phosphate buffer = 8.04.