A buffer solution with a pH of 4.31 is prepared with 1.0 M HC₂H₃O₂ and ________ M NaC₂H₃O₂. The Ka of HC₂H₃O₂is 1.8 × 10^-⁵. A)0.37 B)0.74 C)4.2 × 10^-6 D)8.8 × 10^-10 E)0.18

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The correct answer is A because the Henderson-Hasselbalch equation can be used to calculate the concentration of NaC₂H₃O₂ in the buffer solution. The equation is:pH = pKa + log([A-]/[HA])where pH is the pH of the buffer solution, pKa is the dissociation constant of the weak acid, [A-] is the concentration of the conjugate base, and [HA] is the concentration of the weak acid.In this case, the pH of the buffer solution is 4.31, the pKa of HC₂H₃O₂ is 1.8 × 10^-5, and the concentration of HC₂H₃O₂ is 1.0 M. Substituting these values into the Henderson-Hasselbalch equation, we get:4.31 = 1.8 × 10^-5 + log([A-]/[HA])Solving for [A-], we get:[A-]/[HA] = 10^(4.31 - 1.8 × 10^-5) = 0.37Therefore, the concentration of NaC₂H₃O₂ in the buffer solution is 0.37 M.

A Buffer Solution with a PH of 4