Acids, Bases, and Buffers 2: Unknown Solutions Overview Getting Started Techniques Procedure FAQ Full Lab Manual Introduction & Goals Chemistry & Background Key Questions Prelab Problems Safety Procedure In Your Write-up Appendix Experiments Index ChemLab Home		Possible Unknown Acids, Bases, and Buffers This Table contains the possible acids and conjugate acids of possible bases. Buffers could be composed of any tabulated acid and its conjugate base. Table 1: Weak Acids, Ka, and pKa values Acid HA A- Ka pKa Acetic CH3COOH CH3COO- 1.76 x 10-5 4.75 Ammonium NH4+ NH3 5.6 x 10-10 9.25 Benzoic C6H5COOH C6H5COO- 6.46 x 10-5 4.19 Carbonic H2CO3 HCO3- 4.3 x 10-7 6.37 HCO3- CO32- 4.8 x 10-11 10.32 Chloroacetic CH2ClCOOH CH2ClCOO- 1.4 x 10-3 2.85 Citric C6O7H8 C6O7H7- 7.41 x 10-4 3.13 C6O7H7- C6O7H62- 1.74 x 10-5 4.76 C6O7H62- C6O7H53- 3.98 x 10-7 6.40 Formic HCOOH HCOO- 1.77 x 10-4 3.75 Phosphoric H3PO4 H2PO4- 7.52 x 10-3 2.12 H2PO4- HPO4-2 6.23 x 10-8 7.21 HPO42- PO43- 2.2 x 10-13 12.67 TRIS (HOCH2)3CNH3+ (HOCH2)3CNH2 8.32 x 10-9 8.08
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