| Measure | Value |
|---|
pH values are calculated exactly from the moles of acid and base (a full charge balance at 25 °C, Kw = 1.0 × 10⁻¹⁴). The analyte is always 25.00 mL. The particle circle shows the main species, not real numbers; spectator ions are included only for strong acids and bases.
| Measure | Buffer | Water |
|---|
Both beakers hold 100 mL and get identical drops (each 0.50 mmol of HCl or NaOH; volume change ignored). pH is calculated exactly; each particle stands for 0.50 mmol.
The picture updates with the answer you type. The worked solution builds line by line, explains each log step, and shows units cancelling where moles are involved.
Your job
Drag a card onto a box, or tap a card and then tap the box's name. Cards are buttons, so Tab and Enter work too.
Teaching models with rounded values. Not medical advice.
Wrong picks are fine here. Each one tells you why.