AP Chemistryeasymcq1 pt
A buffer works best when its pH is within what range of its pKa?
A.±1 unit
B.±5 units
C.Exactly at pKa only
D.Below pH 3
Explanation
Core Concept
Within pKa ± 1, the [A⁻]/[HA] ratio stays between 10:1 and 1:10, so both partners remain abundant enough to buffer.
Correct Answer
A±1 unit
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