A 1.0 L buffer solution is 0.250 mol L^-1 CH₃COOH and 0.050 mol L^-1 CH₃COOLi. Which of the following actions will exceed the capacity of the buffer? A) adding 0.050 moles of CH₃COOLi B) adding 0.050 moles of CH₃COOH C) adding 0.050 moles of HCl D) adding 0.050 moles of NaCl E) adding 0.050 moles of NH₄Cl

Question

Quizplus · Accepted Answer

The buffer capacity is determined by the ratio of the concentrations of the conjugate acid-base pair. In this case, the conjugate acid is CH₃COOH and the conjugate base is CH₃COOLi. The buffer capacity will be exceeded if the amount of H+ or OH- ions added is enough to consume either the CH₃COOH or the CH₃COOLi. Adding 0.050 moles of HCl will produce H+ ions that will react with the CH₃COOH and shift the equilibrium towards the CH₃COOLi side, consuming the CH₃COOH and reducing the buffer capacity. Therefore, option C is the correct answer.

A 10 L Buffer Solution Is 0