In this article, I have explained about pH value and its definition and the importance of pH in our daily life. I suggest you to read indicators before read it. You can also read other chemistry articles.
What is pH?
Before you understand that what is meaning of pH. Let’s us understand the term pH, the letter p in pH stands for ‘potenz’ in German. It means power and H stands for hydrogen. It means the full form of pH is power of hydrogen. A solution which has pH value 7 is considered neutral. And if the pH value below 7 acidic and above 7 basic.
Definition of pH scale
The scale which measures the concentration hydrogen
ion in a solution is called pH scale. A pH scale ranges from 0 (very acidic) to
14 (very alkaline).
PH Value: The negative logaritium
of concentration of hydrogen ion in moles per liter.
PH = - log [ H+]
log [ H+] = - PH
I) pH value for water or neutral solutions: pH = 7
ii) pH value for acidic solutions: pH < 7
iii) pH value for basic solution: pH >
7
Universal indicator:
Universal
indicator is use for identify the nature of a solution. Universal indicator is
a mixture of a large number of indicators. Universal indicator shows different color
over the range of pH value from 1 to 14 for a given solution. These type of the
indicators shows a specific colour at a given pH. A colour guides is furnished
with the bottle of the indicator or the strips of paper impregnated with it
which are known as pH paper strips. The solution is tested with drops of the
any universal indicator. Or a drop of the solution is put on a pH paper. The
colour of the solution on the pH paper is compared with the colour chart or guard
and pH is read from this. The pH values obtained from it are only approximate
values
THEORY: The pH is the measure of
the acidic or basic power of any type of solution. It is a scale for measuring the
concentration of hydrogen ion in a solution. The pH scale ranges from 0 to 14.
At 25 °C or 298 K a neutral solution has pH = 7. A value less than 7 on the pH
scale then it represents an acidic solution. Whereas pH value more than 7 then
it represents basic solution. Normally, a pH paper impregnated with the
universal indicator is used for finding the approximate pH value. It shows
different colours (red, yellow, green, etc.) at different pH.
Importance of pH in everyday life
The
role of pH in our life is very important. Some examples of them are described
here.
(a) Acid Rain: When the pH value
of rain water falls below 5.6 then it is called acid rain. When acid rain flows
into rivers then the pH value of the river water also falls and it became
acidic. After that survival of aquatic life become difficult.
(b)pH in plants: Plants have a
healthy growth only when the soil has a specific pH range which should be
neither highly or alkaline nor lower or acidic.
(c) In digestive system: Our stomach produces
hydrochloric acid or HCl which helps in digestion of food. When we eat spicy
food then stomach produces too much of hydrochloric acid which causes ‘acidity’
that is irritation and sometimes pain too. To get rid of this pain we use ‘antacids.
Which are bases like ‘milk of magnesia’ or suspension of magnesium hydroxide in
water.
(d) Self defence of animals and
plants: When Bee sting then it causes severe pain and burning sensation. It is
due to the presence of methanoic acid in this. Use of a mild bases like baking
soda can gives relief from this pain.
Some plants like ‘nettle plant’ have fine
stinging hairs. When they inject it then it releases methanoic acid in our body
of any animal or humans. This is causes of pain and buring sensation. The
leaves of dock plant which grows near the nettle plant when it rubbed on the
affected area then it gives relief.
(e) Tooth decay: Tooth enamel is formed
by calcium phosphate. This is the very hardest substance in our body and can
withstand the effect of various food articles that we eat. If we do not wash
our mouth properly after every meal then the food particles and sugar and other
thigs remaining in the mouth undergoes degradation due to the bacterial present
in the mouth. This process releases acids and the pH value go below 5.5. This is
reason of tooth decay.
In this article, we learn about pH
value and its definition and importance of pH in everyday life.