The concentration of Hydrogen cations H+ in a given solvent defines acidity of the solution. Because this number is very small a log is used to express the acidity or alkalinity. The negative log of H+ concentration bears the term pH. The scale of pH is from 0 to 14. Thus, this is a 10-fold difference of H+ concentration between pH of 6 and 7. Acidosis refers to low pH and alkalosis treats high pH. Water is neutral and has a pH of 7.
PH can be measured directly. Special reagents change their color in different environments. Paper, impregnated with sensing chemical compound (for example, litmus) is submerged into a substance. Within seconds the color changes according to pH level. After that, the colored piece of paper is compared to a chromatic nomogram. This method is simple, but depends much on the observer and cannot be applied to scientific research. Another method requires sophisticated equipment and provides accurate data. However, pH-metry is not difficult to conduct. In this experiment pH meter Model Hanna HI 98212 is used.
Direct measurement of pH may challenge common beliefs about acidity and put visions onto scientific basis. Below are just a few examples of how important it is to understand the theory and practice of pH measurement.
It generally believed that peppers taste â€˜hot’ due to their low pH. Albeit, there are several molecules in the pepper that contribute to its specific taste. Capaisin, the most known of them had been isolated fifty years ago and now is a compound of pain relievers.
Should acidic juice from the stomach reflux into esophagus pyrosis develops. Heartburn is a burning feeling in the middle of the chest, which may sometimes worsen to cough, vomiting or even respiratory disorders. Those who suffer from heartburn are aware to avoid hot sauces, coffee and spices.