For 0.045 M H₂CO₃, a weak diprotic acid, calculate 

(a) [H₃O⁺], 

(b) [HCO₃^-],

(c) [CO₃^2-]. 

Use data from Table 16.5 as necessary.

Table 16.5

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TABLE 16.5 lonization Constants of Some Polyprotic Acids Acid lonization Equilibria H₂S + H₂O HS + H₂O Hydrosulfurica Carbonic Citric Phosphoric Oxalic Sulfurous Sulfuricd H₂CO3 + H₂O HCO3 + H₂O = H₂C6H₂O7 + H₂O = H₂C6H5O₂ + H₂0 HC H₂0₂²- + H₂0 H₂PO4+H₂O → H₂PO4+H₂0 H₂O+ + HS- H3O+ + S²- H3O+ + HCO3- Ka H₂O+ + CO3²- K₁ = 4.7 x 10-11 H₂O+ + H₂C6H5O₂K₁₁ = 7.5 x 10-4 H3O+ + HC6H₂O2- Ka = 1.7 x 10-5 H₂O+ + C₂H₂O₂³- H3O+ + H₂PO4 H30++ HPO4²- HPO4²- + H₂0 — H3O+ + PO4³- H₂C₂O4+H₂0 H3O+ + HC₂04 HC₂04 + H₂0 H3O+ +C₂04²- H₂SO3 + H₂O H3O+ + HSO3- HSO3 + H₂0 H3O+ + SO3²- lonization Constants, K Ka, = 1.0 x 10-7 Ka = 1 × 10-19 H₂SO4+H₂O H₂O+ + HSO4 HSO4+H₂O = H₂O+ + SO4²- Kaz K₂ = 4.4 x 10-7 K₁₁ = 7.1 x 10-3 K₁₂ = 6.3 × 10-8 = 4.0 x 10-7 Kaz = 4.2 X 10-13 K₁₁ = 5.6 x 10-2 Kaz Kaj = 5.4 x 10-5 = 1.3 x 10-2 = 6.2 × 10-8 Kaj Kaz = very large = 1.1 x 10-2 pk pka₁ pka₂ = 7.00 = 19.0 pk₁₁ pka2 = 10.33 pKa = 3.12 = 6.36 pK₂ = 4.77 = 2.15 pka3 = 6.40 pk ₁₁ pka2 = 7.20 = 12.38 pKaz pKay pKaz pka₁ pka₂ = 7.21 = 1.25 = 4.27 = 1.89 PK₁₁ <0 pKaz = 1.96 Acid strength