What is the pH scale?
The pH scale is used to determine whether a substance is acidic or basic, and to calculate how strong a chemical it is. A pH value is a number that ranges from 1 to 14 for most common chemicals, with seven being the middle or neutral point. Values below 7 are indicators of acidity, which increases as the number decreases, while values above 7 indicate alkalinity, which increases as the value increases. One interesting thing to note here is that the pH scale is not a linear scale. In other words, an acid with a ph of 3 is not twice as strong as an acid with a pH of 6. An important distinction to understand is that the pH scale is a logarithmic scale.