acid and a base, depending on the environment it is in. Figure 54 describes amphoteric molecules:
Figure 54.
PH SCALE The pH is very important when it comes to recognizing whether or not a substance is an acid or base in solution chemistry. This is based on the concentration of hydrogen ions in a solution. The basic formula is that the pH equals the negative log of the hydrogen ion concentration. It is generally thought of as a scale from 1 to 14 but it is somewhat incorrect, as you’ll soon see. A pH of 7 is directly neutral, while a pH of 1-7 is acidic and a pH of 7-14 is considered basic. Figure 55 shows the pH scale:
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