pH in daily life


pH is an essential part of life. Many of our internal processes such as digestion, excretion and circulation support their activities based on the pH factor. pH is the hydrogen ion concentration in a given sample and it is a widely applicable phenomenon in the field of chemistry. The majority of the chemicals are being classified based on their reaction with the litmus paper( acidity or alkalinity). Litmus paper is a paper used to identify the acidity or alkalinity of a sample. Based on the hydrogen ion concentration, the 3 commonly found states of substance reactions are acidic, alkaline and neutral. The following section describes briefly about the basic concepts of pH and how they help in human welfare.


pH in our daily life

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 elements. The strength of a given substance depends upon the concentration of H+ or OH– ions in the samples.  To measure the H+ and OH- concentration, the pH scale is used. The p in pH stands for ‘potenz’ in the German language meaning, power. A pH scale visually represented as a continuum from 0 to 14. Zero (0) indicates the most acidic state whereas  7 is the neutral state and anything beyond 7 alkaline state.  The OH- and H+ are the 2 contrary states because,  as 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, whereas if it`s H+ level goes high then it is acidic .pH is closely linked with many of our day-to-day affairs as explained below.


pH and the digestive system

Our stomach contains Hcl (hydrochloric acid) and stomach juices are highly acidic with many enzymes in it. Juices in the stomach has a pH of around 1.2 which is highly acidic that doesn't encourage the growth of the majority of the microbes. The enzymes found in the stomach juices helps in protein digestion. Nevertheless, excess of hydrochloric acid can lead to acidity in the stomach consequently resulting in the 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 color codes produced when the litmus is dipped in a given sample. On the other side, if the soil is too alkaline then, adding gypsum will neutralize the excess alkali present in the soil.


color codes for pH


pH and tooth decay

Tooth enamel is made up of calcium tetra phosphate,  a very hard covering layer of teeth helps 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, the decayed food produces an excess of acid and plaque allowing the enamel to be slowly destroyed. Hence, it is important to keep the control over pH levels in the mouth by regularly brushing them, and we must also avoid eating sugary foods because sugar attracts microbes resulting in the formation of plaque.


pH and the chemical warfare

Secretions and poisons of many plants and animals used in the warfare because of their nature of extreme acidity or alkalinity. 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 causing chronic pain. 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 because 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 because, the citric acid present in the tamarind react with the basic copper oxide or copper carbonate. 


Further reading


Chemical reactions and equations


Chemical thermodynamics




 Acids, bases and salts



  1. Name the body organ where pH is highly acidic  

  2. What is pH?

  3. Explain the litmus paper test to identify pH

  4. Why pH is essential for plants?

  5. What is the role of pH in blood?

  6. Explain the pH scale.

  7. How pH and tooth decay are related?

Welcome to innoclazz Academy; one of the leading portal to provide home tutors across the country. If you are looking for a personal teacher we request you to register at Innoclazz academy. We provide home tutors in bangalore. You may also contact us for the best home tutors in Chennai, Hyderabad and Mumbai. You can also submit a demo request here





Course List