Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is the best choice for making a buffer solution with an optimum pH in the range of 3.1-3.5? 00000 NaNO₂/HNO2 (K₂=4.6 x 10-4) KCH3COO/CH3COOH (K₂ = 1.75 x 10-5) CH3NH2/CH3NH3CI (K₂ = 2.3 x 10-11) NaOCN/HOCN (K₂ = 2.0 x 10-4) NaNO3/HNO3

For 480.0 mL of a buffer solution that is 0.160 M in CH3CH2NH2 and 9.00×10−2 M in CH3CH2NH3Cl , calculate the initial pH and the final pH after adding 1.5×10−2 mol of HCl . ( Kb(CH3CH2NH2)=5.6×10−4 .)

A buffer solution is 0.463 M in H3PO4 and 0.210 M in KH₂PO4. If K₁1 for H3PO4 is 7.5 × 10-³, what is the pH of this buffer solution? pH =

What is the pH of the solution that results from mixing 25 mL of 2.20×10-2 M NH3 and 25 mL of 2.20×10-2 M HCl? Ka (NH4+) = 5.60×10-10 pH =

Calculate the pH of a buffer solution that is 0.200 M in HCN and 0.120 M in NaCN.  The Ka of HCN is 4.90 x 10-10.

Assuming equal concentrations of conjugate base and acid, which one of the following mixtures is best suited for preparing a buffer solution with pH of 4.74?   Question 2 options:   NH3 / NH4Cl  (Ka = 5.6 × 10–10)   NaNO2 / HNO2  (Ka = 4.5 × 10–4)   CH3COONa / CH3COOH  (Ka = 1.8 × 10–5)   NaCl / HCl   NaOCl / HOCl  (Ka = 3.2 × 10–8)

What is the pH of a solution prepared by mixing 20.0 mL of 0.50 M NaOH and 35.0 mL of 0.50 benzoic acid solution? (Benzoic acid is monoprotic with a Ka of 6.5 x 10-5.)

The K, for NH3 is 1.8 x 10-° at 25°C. Calculate the pH of a buffer solution made by mixing 45.7 mL of 0.493 M NH3 with 62.0 mL of 0.438 M NH4 Cl at 25°C. Assume that the volumes of the solutions are additive. pH =

A 1.30 L buffer solution consists of 0.313 M propanoic acid and 0.190 M sodium propanoate. Calculate the pH of the solution following the addition of 0.069 mol HCl. Assume that any contribution of the HCl to the volume of the solution is negligible. The K₂ of propanoic acid is 1.34 × 10-5. pH =

Calculate the pH of a buffer solution that is 0.200 M in HCN and 0.120 M in NaCN. The Ka of HCN is 4.90 x 10-10.