0.3M Na2HPO4
Example #1: Determine the pH of 0.300 M sodium hydrogen phosphate, Na₂HPO4.
Phosphoric acid, H3PO4, contains K₁₁ = 7.5 x 10-3, K₂ = 6.2 x 10-8 and K₁3 = 4.2 x 10-13.
al
a2
a3
x²
0.2x=4.2X10-13
x² = 1.26×10-¹3/- 0.₁126×10/2
x = 0.355x100
HP04² = H30t+ P04²
0.3
0.3-X
+x +X
X X
3-
04-beg[+0]- (6.459.78
PH=
Simp
-6