Question

By definition, a solution containing a large number of hydroxide ions is best defined as _________.

Answer 1

My guess is on B since Hydroxide ions are OH- which is a basic ion not an acid (which can be symbolized by H+) and not D since its a theory that certain ions are acids.<span />

Answer 2

According to  Arrhenius acid base theory

a) an acid is which gives proton in an acid base reaction

b) a base is which gives hdyroxide ions in an acid base reaction

Now as given that a solution containing a large number of hydroxide ions then it must be an Arrhenius base.

For an example

KOH ---< K+⁺ + OH⁻

Thus solution of potassium hydroxide will have large number of hydroxide ions and it is an arreheius base