Virtual Buffer Prep Bench — make it, then QC it
Walk the full procedure in the correct order — weigh → dissolve → adjust pH → bring to volume → QC. The bench tracks what you actually did and grades the result against a quality-control checklist of the classic mistakes.
1 Do each step in order
2 Watch the live pH respond to your actions
3 Read the QC report & fix what failed
Changing the task resets the bench.
Bench readouts
pH probe (assumed calibrated)
—
awaiting solution
Teaching model: activity is treated as equal to concentration and ionic strength is ignored, so a real meter may differ by a few hundredths of a pH unit. Polyprotic buffers (phosphate) use a single relevant pKa, and the probe is assumed perfectly calibrated. Temperature shifts pKa via pKa(T) = pKa(25 °C) + (ΔpKa/°C)·(T − 25). Always confirm with a calibrated meter for real lab work.