Preparation of Buffer Solution with Disodium Hydrogen Phosphate

Disodium hydrogen phosphate (Na₂HPO₄) can be used as a buffer solution alone or mixed with other solutions as a buffer solution widely used in various analytical tests.

1. Na₂HPO₄ - NaH₂PO₄ Buffer Solution (0.2 mol/L)

Note: Na₂HPO₄·2H₂O relative molecular weight = 178.05, 0.2 mol/L solution is 35.61 g/L.

Na₂HPO₄·12H₂O relative molecular mass = 358.14, 0.2 mol/L solution is 71.64 g/L.

NaH2PO4·2H₂O relative molecular weight = 156.03, 0.2 mol/L solution is 31.21 g/L.

2. Na₂HPO₄ - KH₂PO₄ Buffer Solution (1/15 mol/L)

Note: Na₂HPO₄·2H₂O relative molecular mass = 178.05, 1/15 mol/L solution contains 11.876 g/L.

KH₂PO₄ relative molecular mass = 136.09, 1/15 mol/L solution contains 9.078 g/L.

3. Na₂HPO₄ - Citric Acid Buffer Solution

Note: Na₂HPO₄·2H₂O relative molecular mass = 178.05, 0.2 mol/L solution is 35.61 g/L.

Na₂HPO₄ relative molecular weight = 141.98, 0.2 mol/L solution is 28.40 g/L.

Citric acid relative molecular mas = 210.14, 0.1 mol/L solution is 21.01 g/L.