Sometimes these compounds are referred to by their trivial names. They are
monochloramine, dichloramine and trichloramine.
Now that we have met these chlorine compounds we can divide them into two categories.
Free available chlorine includes C12, HOCl and OCl-. Combined available chlorine covers the
three chloramine compounds. Although the chlorine has reacted with ammonia, it is still
referred to as "available" because the chloramines have some disinfecting capability