Question 1

How do you calculate pH from acid concentration?

Accepted Answer

For strong acids, pH ~ -log10[H+]. For weak acids, use Ka and solve the equilibrium or use the Henderson-Hasselbalch equation for buffers.

Question 2

What is the relation between pH and pOH?

Accepted Answer

pH + pOH = 14.00 at 25 C because Kw = 1.0e-14 in pure water at that temperature.

Question 3

How do buffers work?

Accepted Answer

Buffers contain a weak acid and its conjugate base; pH ~ pKa + log10([base]/[acid]) within the buffer range.

Question 4

Do temperature and ionic strength matter?

Accepted Answer

Yes—Kw and activity coefficients change with temperature and ionic strength, shifting pH slightly.

Question 5

Can I compute pH of mixtures?

Accepted Answer

Simple mixtures can be approximated; exact results need full equilibrium and charge balance.

pH Calculator — Acid & Base Chemistry Calculator