Question

For what does `pH` stand?

Answer 1

Originally `pH` stood for pouvoir hydrogene, and is formally defined on the logarithmic scale, `pH = -log_10[H^+]`

Explanation:

Given the defintion if `pH = 7`, then `[H^+] = 10^-7 mol L^-1`. More positive `pH` values describe alkaline solutions, whereas smaller or negative `pH` values identify more acidic conditions.

Solution concentration is generally defined by "moles of solute per volume of solution".