A pH number is the beginning of an explanation — Physical Science: Chemistry

pH describes hydronium activity logarithmically. A one-unit difference corresponds to a tenfold activity difference, not one extra ion. Acid strength, formal concentration and pH are distinct: a dilute strong acid and a more concentrated weak acid can give similar pH. Neutral pH follows the water equilibrium at the stated temperature rather than an absolute rule that every neutral sample must be pH seven.

Before a mixed-solution pH calculation, count reacting amounts and apply the chemical ratio. A titration’s equivalence point is stoichiometric, while an endpoint is an observed signal with uncertainty. Strong-acid/strong-base and weak-acid/strong-base curves have different regions. At the latter’s equivalence, conjugate-base reaction with water can produce a basic pH.

A buffer has appreciable conjugate components. Added strong acid or base first changes their amounts; the remaining ratio then supports an approximate equilibrium calculation. Two buffers with the same ratio can have similar initial pH but very different capacities. Keep the full calculated titration figures separate from the investigation’s supplied illustrative records, and do not treat either as measurements you personally collected.