Acids & Bases - Chemistry

Acids & Bases 22Explaination for j) on the last page:The actual hydroxide concentration for any basedissolved in water is more precisely defined as:[OH − ]total = [OH − ]base + [OH − ]waterNormally, [OH − ]water is 1 × 10 −7 M and is muchless than [OH − ]base, thus we can usually ignore it.BUT, in this example, [OH − ]base turns out to beonly 1 × 10 −14 M, much less than the [OH − ]water.So in this example we can actually ignore the tinyamount of OH − contributed from the base and onlyconsider the OH − naturally present in water:This will work for base concentrations of 1 × 10 −8 M andlower. It gets complicated mathematically right around1 × 10 −7 M (not dealt with in this course).