This is the boss. No calculator — every concentration is pinned to an exact power of ten, so the logs are mental. One unknown acid runs the whole gauntlet: the burette finds its concentration, the log turns that into a pH, the see-saw hands over the pOH — and every answer feeds the next line. Write each line down; one early slip rides the cascade to the end.

The acid is strong — fully dissociated — so $[\mathrm{H^+}]$ IS the concentration the titration finds. Everything from the chapter reports for duty. 5★ under par here is the chapter crown. Swirl the flask, watch the colour, clock in.