any of the major appearances or aspects in which a thing of varying modes or conditions manifests itself to the eye or mind. 2. a stage in a process of change or development: Each phase of life brings its own joys. 3. a side, aspect, or point of view: This is only one phase of the question.
The pH of a neutral solution is 7. At this pH, the solution has equal concentrations of both the H+ and OH- ions, which is 10^-7 mole/litre. The presence of both the hydrogen and hydroxyl ions in equimolar concentrations makes the solution neutral.
In a neutral solution the concentration of [H + ] and[OH - ] ions is balanced at 10 -14 , moles perliter of each (and the product [H + ][OH - ] =10 -14 ,). If you plug that back into the definition of pHyou will see it gives a value of pH = 7 so neutral solutions have apH of 7.