Given the following ionic compounds which have the highest will have the highest concentration of hydroxide ions. Concentration. Here it says HINT, which is the most soluble in water. All right, so if we took a look at every single one of these compounds, you will see that they all break up into three ions. They would break up into the respective metal and two hydroxide ions.
Now, because they break up into the same number of ions, we can just look at their KSP values and determine which one would produce the most. OH-. Remember the grittier KSP value. The more soluble your ionic solid will be, the more ions it will produce. So if we take a look here, 10-17 to the 10-20 to the 10-13 to the 10-27 here, we'd say magnesium hydroxide is our answer.
It has the highest KSP value, therefore it is the most soluble, meaning that it will break up the most and produce the most OH- ions as products. This in turn will create the highest hydroxide ion concentration.
