Definition
In aqueous solution, an acid is defined as any species that increases the concentration of \text{H}^+(aq)H+(aq)start text, H, end text, start superscript, plus, end superscript, left parenthesis, a, q, right parenthesis, while a base increases the concentration of \text{OH}^-(aq)OH−(aq)start text, O, H, end text, start superscript, minus, end superscript, left parenthesis, a, q, right parenthesis. Typical concentrations of these ions in solution can be very small, and they also span a wide range.
For example, a sample of pure water such hairy numbers, scientists convert these concentrations to \text{pH}pHstart text, p, H, end text or \text{pOH}pOHstart text, p, O, H, end text values. Let's look at the definitions of \text{pH}pHstart text, p, H, end text and \text{pOH}pOHstart text, p, O, H, end text.
