A buffer solution typically consists of a weak acid and its conjugate base, maintaining the pH by neutralizing added acids or bases. In this case, the buffer solution contains acetic acid ([tex]\(HC_2H_3O_2\)[/tex]) and its conjugate base, acetate ([tex]\(C_2H_3O_2^-\)[/tex]), provided by potassium acetate ([tex]\(KC_2H_3O_2\)[/tex]).
Let’s analyze each action step-by-step to determine which will destroy the buffer:
1. Adding 0.050 moles of HCl:
- HCl is a strong acid and will dissociate completely in water.
- It will react with the acetate ions ([tex]\(C_2H_3O_2^-\)[/tex]) to form acetic acid and chloride ions.
- The reaction is: [tex]\(HCl + C_2H_3O_2^- \rightarrow HC_2H_3O_2 + Cl^-\)[/tex]
- Given that the initial buffer has more [tex]\(C_2H_3O_2^-\)[/tex] ions (0.250 M) than [tex]\(HC_2H_3O_2\)[/tex] (0.050 M), adding 0.050 moles of [tex]\(HCl\)[/tex] will shift the balance but it will not completely consume the acetate, so the buffer's ability will be challenged but not completely destroyed.
2. Adding 0.050 moles of NaOH:
- NaOH is a strong base and will dissociate completely in water.
- It will react with the acetic acid ([tex]\(HC_2H_3O_2\)[/tex]) to form acetate ions and water.
- The reaction is: [tex]\(NaOH + HC_2H_3O_2 \rightarrow C_2H_3O_2^- + H_2O + Na^+\)[/tex]
- Since the buffer initially has equal molar amounts of acetic acid (0.050 M) and 0.050 moles of NaOH, the acetic acid will be neutralized, leaving more [tex]\(C_2H_3O_2^-\)[/tex] ions in the solution.
- This will maintain the buffer, as the acetate concentration will increase, but not destroy it.
3. Adding 0.050 moles of [tex]\(KC_2H_3O_2\)[/tex]:
- Potassium acetate is a source of acetate ions.
- Adding more [tex]\(KC_2H_3O_2\)[/tex] increases the concentration of [tex]\(C_2H_3O_2^-\)[/tex], strengthening the buffer’s basic component.
- However, this action will not destroy the buffer as it will still have the required components intact.
4. Adding 0.050 moles of [tex]\(HC_2H_3O_2\)[/tex]:
- Adding more acetic acid will increase its concentration in the buffer.
- This strengthens the acidic component of the buffer but does not destroy it.
Conclusion: Based on this analysis, none of the four actions will outright destroy the buffer. Each action either strengthens one part of the buffer system or challenges its balance but does not completely render it ineffective.
Thus, the statement "All of the above will destroy the buffer" is incorrect. None of the specified actions will destroy the buffer.
