pH in daily life


pH is an essential part of life. Many of our internal processes such as digestion, excretion, circulation carry out their activities based on the pH factor. pH is the hydrogen ion concentration in a given sample. pH is widely applicable in the field of chemistry because the majority of the chemicals are being classified based on their reaction towards litmus paper. Based on the hydrogen ion concentration, the 3 commonly found states of substance reactions are acidic, alkaline and neutral. The following section describes briefly basic concepts of pH and how they help in human welfare.

Table of contents

1. Introduction

2. pH scale (Strength of acids and alkaline solutions)

3. pH and the digestive system

4. pH and the plants

5. pH and tooth decay

6. pH and the chemical warfare

7. The tarnished surface of Copper vessel and the acidity of                       lemon/tamarind!


pH scale (Strength of acids and alkaline solutions)

Different acids and alkalies carry different hydrogen ion strengths and this is what makes them react differently when combined with other chemicals or elements. The strength of a given substance depends upon the concentration of H+ or OH– ions in the samples.  To measure the hydrogen and OH concentration, the pH scale is used. The p in pH stands for ‘potenz’ in the German language meaning, power. A pH scale is a continuum of 0 to 14, 0 indicates the most acidic state whereas  7 is the neutral state and anything beyoned 7 alkaline state.  Similarly  OH- and H+ are the 2 contrary states because,  when one increases, the other one decreases and vice-versa. The pH of OH-solution tend to more than 7 but the pH of an H+ solution is less than 7 /. When OH levels raise,  the solution turns into alkaline form, suppose it`s pH drops then it is acidic .pH is associated with many of our day to day affairs as explained below.


pH and the digestive system

As you already know that our stomach contains Hcl( hydrochloric acid) and stomach juices are highly acidic. Juices in the stomach has a pH of around 1.2 which doesn't allow most of the microbes to survive. The enzymes found in the stomach juices helps in protein digestion. Nevertheless, excess of hydrochloric acid can lead to acidity in the stomach. Acidity causes stomach pain and burning sensation in the stomach. Acidity can be treated with 2 common antacids are Milk of Magnesia (Magnesium Hydroxide) and Sodium Bicarbonate (Baking soda).


pH and the plants

pH is a major factor in crop production. Different plants require a specific pH levels in their soil as pH acts differently on against different soils. If the soil is too acidic then its pH can be raised by adding lime (or slaked lime) which neutralizes the excess acid in the soil. The following image is the description of colour codes produced when the litmus is dipped in a given sample. 

color codes for pH

On the other side, if the soil is too alkaline then, adding gypsum will neutralize the excess alkali present in the soil.


pH and tooth decay

Tooth enamel is made up of calcium tetraphosphate, it is a very hard covering layer of teeth to protect them. The enamel is not affected by water and natural foods but they get corroded slowly when pH in the mouth falls below 5.5. Such an environment develops plaque as a result of food particles being lodged in between the tooth for a long time. If the oral hygiene is poorly maintained, then the decayed food produces an excess of acid and plaque which will destroy our enamel. We must also avoid eating sugary foods because sugar attracts microbes to produce plaque and acid.


pH and the chemical warfare

Secretions and poison of many plants and animals used in the warfare are either be too acidic or highly alkaline in their pH. This will help to produce painful and irritating symptoms in the victim. For instance, when a honey bee stings a person, it injects an acidic liquid into the skin. Rubbing with a mild alkaline solution like baking soda solution on the stung area of the skin gives relief. The knowledge of pH also helps us in maintaining the proper acidity in many products such as shampoos, medicines, etc. pH of rainwater can be used to detect the extent of certain pollutant gases in the atmosphere.


The tarnished surface of Copper vessel and the acidity of lemon/tamarind!

Copper surfaces are easily tarnished becasue of the formation of the copper oxide layer on their surface. Rubbing the tarnished copper vessel with lemon, or tamarind help in neutralizing the stains becasue, the citric acid present int he tamarind react with the basic copper oxide or copper carbonate. 





Course List