Constantly a certain number of water molecules (2 to 10 billion) break up into charged particles H +, OH- (this, of course, is a simplified interpretation of the phenomenon). pH ? this abbreviation means potential hydrogen (potential hydrogen) or ?hydrogen power? (therefore, they write the capital ?p? and the capital ?H?). pH means the relative concentration of H + and OH- ions in water. The more H +, the higher the acidity of water. The more OH- and, consequently, less H-, the more alkaline the reaction will be in the water. The pH scale is divided into 14 units (from 0 to 14), where 0 is the maximum acidity, 7 is neutral, and 14 is maximum alkalinity.
It is obvious that in pure water the amount of H + and OH- ions is balanced: it is neutral pH or pH 7. With increasing ? + acidity increases, with increasing OH- alkalinity increases. An acid is a compound that releases H + ions when dissolved. Alkali in solution releases OH? ions. Simple examples:
From the table below it becomes clear why the scale has 14 divisions from 0 to 14. In pure water, at neutral pH, the concentration of H + is 1?10-7 per 1 liter. Now I understand where did the seven come from? In fact, the pH value indicates the concentration of H + ions in the solution. At pH 6.1?10-6 H +, etc. The exponent is taken, the minus sign is discarded and we get the pH value. One important distinguishing feature of the scale, which is of great practical importance, is that it is a logarithmic scale. Everything is simple ? at each step the scale increases or decreases by one order of magnitude. For example, at pH 6, H + ions are 10 times greater than at pH 7. At pH 5, H + ions are 100 times greater than at pH 7, etc. And, on the contrary, at pH 8, OH- ions will be 10 times more than at pH 7. At pH 9, OH- ions will be 100 more than at pH 7 (and 10 times more than at pH 8).