Which of the following is true for a buffered solution?
The solution resists any change in its [OH-].
The solution will not change its pH very much even if a concentrated acid is added.
The solution resists any change in its [H+].
All of the the statements are true.*
The solution will not change its pH very much even if a strong base is added.
I agree with some reservations about addition of strong acid or strong base. A buffered solution CAN be overwhelmed wbut with moderate amounts of strong acid or strong base I agree.
If one titrates a buffered solution and a non-buffered solution where both have the same concentration of weak electrolyte (wk acid or wk base), both would have the same equivalence point. The difference is on addition of titrant (e.g., NaOH into HOAc/OAc Buffer vs NaOH into HOAc) the buffered system would demonstrate very little change in pH en-route to the equivalence point whereas the non-buffered system would start at a lower pH (i.e., acidic soln) and demonstrate a much higher pH change for the same amount of titrant added.
The correct answer is "All of the statements are true." A buffered solution is a solution that resists changes in pH when small amounts of an acid or a base are added. It achieves this by containing a weak acid and its conjugate base or a weak base and its conjugate acid. Therefore, a buffered solution resists changes in both [H+] (statement 3) and [OH-] (statement 1). Additionally, because of its buffering capacity, it will not change its pH significantly when either a concentrated acid or a strong base is added (statement 2 and 5).
To determine which of the statements is true for a buffered solution, let's break down each statement and analyze it.
1. "The solution resists any change in its [OH-]."
For a buffered solution, it does not necessarily resist changes in the hydroxide ion concentration ([OH-]). Buffer solutions are designed to resist changes in pH, which is primarily affected by the concentration of hydrogen ions ([H+]), rather than hydroxide ions. So, this statement is not true for a buffered solution.
2. "The solution will not change its pH very much even if a concentrated acid is added."
This statement is true for a buffered solution. A buffered solution contains a weak acid and its conjugate base (or a weak base and its conjugate acid) in nearly equal amounts. These components act as a buffer system, which can absorb or neutralize added acid or base, thus minimizing the change in pH.
3. "The solution resists any change in its [H+]."
This statement is essentially stating the same concept as statement 2, just in terms of hydrogen ions ([H+]). So this statement is also true for a buffered solution.
4. "All of the statements are true."
This statement implies that all the statements given are true. However, since we have identified that statement 1 is not true, this option cannot be correct.
5. "The solution will not change its pH very much even if a strong base is added."
Similar to statement 2, this statement is also true. A buffered solution can resist significant changes in pH, both when an acid or a base is added, due to the presence of the buffer system.
Therefore, the correct answer is: "The solution will not change its pH very much even if a concentrated acid is added" and "The solution will not change its pH very much even if a strong base is added."