Measure how resistant a buffer solution is to changes in pH when acid or base is added.
Testing Parameters
L
M
L
Calculation Results
Enter parameters to calculate the buffer capacity
About this calculator
Overview
Buffer capacity is the measure of 'stubbornness' of a solution against changing its pH. It's like a chemical shock absorber. The higher the capacity, the more acid or base it can 'soak up' before the pH starts to shift significantly.
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Pro Tips
Concentration matters! A 1.0 M buffer is 100 times stronger than a 0.01 M buffer, even if they have the exact same pH.
Buffers are 'directional'. A buffer with more weak base than acid resists acid attacks better, and vice versa.
For pool owners: Cyanuric acid acts as a stabilizer (buffer) for chlorine, protecting it from UV light while also buffering pH.
Temperature changes can shift pKa, meaning a buffer that works in the fridge might be off at room temperature.
When testing experimentally, ensure your pH meter is calibrated, as small errors in ΔpH cause large errors in calculated capacity.
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Fun Facts
"Swimming pools rely on 'Total Alkalinity' (mostly bicarbonate) acting as a buffer. If it's too low, you get 'pH bounce' where pH swings wildly."
"Your blood is an amazing buffer! It stays strictly between pH 7.35 and 7.45. If it drops to 7.0 or rises to 7.8, it can be fatal."
"The ocean is a giant buffer system, but it's getting 'tired'. It absorbs CO₂ to form carbonic acid, but this is slowly overcoming its capacity, leading to ocean acidification."
"Our skin has a natural buffer ('acid mantle', pH ~5.5) that protects us from bacteria. Washing with harsh high-pH soaps can strip this protection."
"In fermentation (beer/wine), natural buffers from the fruit or grain help yeast survive by preventing the liquid from becoming too acidic too quickly."
"Buffer capacity is at its absolute maximum when the pH equals the pKa of the acid component."
