Write fullform of pH and Importance of pH in daily life?
Give reason why does tooth decay start when pH of mouth is
lower than 5.5
Answers
It is defined as the magnitude of the negative power to which 10 must be raised to
express the hydronium ion concentration.
pH=−log[H
+
]
[H
+
]=10
x
pH=x
pH values of the solutions do not give us immediate idea of the relative strengths of the solutions
pH value zero is obtained in solution of strong acid.
A solution of an acid having very low concentration can not have pH 8, as shown by pH formula but the actual pH value will be less than 7.
pH of cheese is between 4.8−6.4.
pH of bananas is between 4.5−5.2.
pH of grapes is between 3.5−4.5.
pH of lime juice is between 2.0−2.4.
Our body works within the pH range of 7.0 to 7.8. Living organisms can survive only in a narrow range of pH change. When pH of rain-water is less than 5.6, it is called acid rain. When acid rain flows into the rivers, it lowers the pH of the river water. The survival of aquatic life in such rivers becomes difficult.
The pH in the human digestive tract varies greatly. The pH of saliva is usually between 6.5 - 7.5. The fundic or upper portion of the stomach has a pH between 4.0 - 6.5, lower portion of the stomach secrete hydrochloric acid (HCI) and pepsin until it reaches a pH between 1.5 - 4.0.
The evolution of chemical defenses in plants is linked to the emergence of chemical substances that are not involved in the essential photosynthetic and metabolic activities.
Wasp stings basic liquid while ants bees injects acid.
When the pH in the mouth falls below 5.5, tooth decay starts. Bacteria present in the mouth produce acid by degradation of sugar and food particles which remain in the mouth after eating. The acid produced in the mouth attack the enamel thereby, creating tooth decay.