ANATOMY

Detailed explanation-1: -The pH scale is used to rank solutions in terms of how acidic or how basic they are. It indicates the concentration of hydrogen ions (H+) and hydroxide ions (OH-) in a solution. These ion concentrations are equal in pure water, which has a pH of 7.

Detailed explanation-2: -[H+]=10-7, which we call a pH of 7. In the same way, a solution with a pH of 5 contains 10-5mol/l of hydrogen ions, a solution with a pH of 6 contains 10-6mol/l of hydrogen ions, while the solution with a pH of 7 contains 10-7mol/l of hydrogen ions.

Detailed explanation-3: -For pure water, the values of [H3O+] and [OH-] are equal and thus their values are both 1.0 x 10-7. If there is an equal amount of acid and base present in any solution, the solution is called “neutral” and the pH of the solution is 7.

Detailed explanation-4: -A neutral pH of 7 indicates that the concentration of (H+) ions is equal to the concentration of (OH-) ions. The lower the pH, the higher the concentration of (OH-) ions compared to the concentration of (H+) ions. The pH of an unknown solution changed from pH 5 to pH 4.

Detailed explanation-5: -In very general terms a solution is said to be neutral when the numbers of hydrogen ions and hydroxyl ions are equal, each corresponding to an approximate concentration of 10−7 moles/l. This neutral point is temperature dependent and occurs at pH 7.0 at 25°C.