The pH Scale

A pH scale measures the concentration of hydrogen ions in a solution; it tests the hydrogen ions amount in any solution. Overall, the concentration of hydrogen ions is reciprocally correlated to its pH, which can be measured on a pH scale. The measure of a pH scale varies from 0 to 14, where most acidic is usually at 0, and the measure of 14 is the most basic. It is therefore important to understand acid and bases with an evaluation of their difference to determine their direct or indirect impact on the hydrogen ion concentration. The trusted measure of hydrogen ion concentration is a pH scale.

Acids and bases are best understood using scientific theories, including Bronsted-Lowry, Lewis, and Arrhenius (Kumar 3). Bronsted-Lowry definition of acids and bases is acids are donors of protons while bases are proton acceptors. Lewis, on the other hand, defines bases as electron-pair donors while acids are electron-pair acceptors. Finally, Arrhenius's theory states that acids generate (H+) ions in their different solutions while bases produce (OH-) ions (Gosh, 4).  From these theories, we can conclude that a pH solution quantifies its alkalinity or acidity.  Solutions with a pH range of 0 to 4 are known as strong acids and form salt and water on reaction with bases. The pH range of 4-7 in a solution is referred to weak acids.

They also contain low concentration hydrogen ions. The reaction with bases is slow and forms precipitates that prevent further reactions. Solutions with a pH of 7 are neutral, which does not affect the hydrogen ion concentration.  Solutions with a pH of 7-10 are called a weak base that reacts with acids at a slower rate, forming less water. Strong bases have a pH range of 10-14 and vigorously react with strong bases as strong bases contain more hydroxide ions (OH-)

The concentration of hydrogen ions in a solution depends on the effects of the pH levels. As earlier explained pH scale ranges from 0-14; the concentration of hydrogen ions by a factor of 10 is represented by a change of one unit on the pH scale, whereas a concentration factor of a 100 represents change of two units on the pH scale (David 5). The changes in concentration of hydrogen ions are represented by a change in the pH, where a small pH change results in large changes in the concentration of hydrogen ions. The change in their pH values can determine the direct and indirect effects of acids and bases.

Hydrogen ion concentration of a solution refers to the potential of hydrogen of a solution. The addition of acids or bases affects the hydrogen ion concentration. When a strong acid is added to a buffer solution, the conjugate base present in the buffer consumes the hydronium ions converting to water.  As a result, the amounts of conjugate base present decreases and an increase in a weak acid; pH of the buffer solution decreases by a small variation.

On the other side, when a strong base is added to a buffer solution, weak acids consume the hydroxide ions resulting in a weaker conjugate base of the acid and water formation. The amount of weak acid decreases while that of the conjugate base increases, preventing the solution's pH from rising, which would occur in the absence of buffer solution. A buffer solution is one whose pH is resistant to adding either a strong base or acid. It is used to determine the effect of acids or bases on the concentration of hydrogen ions. Adding base in a solution increases hydroxide ion concentration as bases contain (OH^-), which neutralizes the (H⁺) and further increases the ph. The pH range of bases is 7 to 14. The addition of acids increases the concentration of hydrogen ions which lowers the pH as strong acids with concentrations that are tighter contain more replaceable hydrogen ions (David 5).