The document summarizes a presentation on pH and buffers. It defines pH as the negative log of the hydrogen ion concentration and describes how pH is measured using pH strips, indicators, or a pH meter. It explains that the pH scale ranges from 0 to 14, with values below 7 being acidic and above 7 being basic. Buffers are described as mixtures of weak acids and bases that can resist changes in pH when small amounts of acid or base are added. Examples of buffer systems in the human body that regulate pH are also mentioned.

1. I.P (P.G) COLLEGE [Campus-2]
Bulandshahr
 Presented on the topic : pH and Buffer
 Presented by : HIBA ANSARI
BSc. (Biotec. 1st year)
Given by: Mr. Harsh sir

2. Content
pH
•Introduction
•What is ph?
•Measurement of pH
•What is pH scale
•pH facts
•Importance of pH
Buffer
Types of buffer
Buffer system in body
fluid

3. pH
 Introduce in 1909 by Danish chemist Soren P. L.
Sorenson at Carlsberg Laboratory.
 The exactly meaning of ‘pH’ is ‘potential of hydrogen’
 Measurement of pH are important in:
 Biology
 Chemistry
 Agriculture
 Forestry
 Food science
 Water purification
 Water treatment

4. It is defined as negative log of
hydrogen ion concentration
What Is pH?

5. Measurements of pH
 The pH can be measured by:
pH strips
pH indicators
pH meter

6. pH Strips

7. pH indicator

8. pH meter
The pH meter is a laboratory equipment
which used to measure acidity or
alkalinity of a solution

9. What is pH scale?
•A scale with values ranging from below 0
to above 14 is used to measure pH is
known as pH scale.

10. Acid and Base
 Substance with a pH above 7 are basic.
 A base is any substance that forms hydroxide ions (-
OH) in water.
 For example ; NaOH (sodium hydroxide) ,
NH4OH(ammonium hydroxide).
 Substance with a pH below 7 are acidic .
 An acid is any substance that forms hydrogen ions
(H+).
 For example ; vineger(carbonic acid),acetic acid (soda
water).

11. Ph Facts
Item pH
Human Blood 7.41
Ocean Water 8.2
Acid Rain <5.6
Milk ~6.4
Beer 4-5
Vinegar ~3
Distilled Water ~4.5

12. Importance of pH
pH plays significant role in
biochemical reactions.
For example;
-the blood in our bodies is
maintained at a pH value of
7.35-7.45.
-the stomach produces HCl
that helps in the digestion of
food.

14. What is Buffer?
 It is an aqueous solution consisting of a mixture of
weak acid and its conjugate base or weak base and its
conjugate acid.
 It can resists change in pH when small amount of acid
or base is added.
 Basically it is use in keeping the pH at a nearly
constant value in a wide variety of chemical
application.

15. Types of Buffer solution:
 There are two types of buffer solution
1. Acidic buffer
2. Basic buffer

16. Acidic Buffer
 Acidic buffer is a combination of weak acid with its
salt with a strong base.
i.e. Weak acid and salt with strong base(conjugate
base)
 For example;
CH3COOH +CH3COONa
(weak acid) (salt)

17. Basic Buffers
 A basic buffer is a combination of weak base and its
salt with a strong acid .
i.e. Weak base and salt with strong acid(conjugate acid)
 For example;
NH4OH + NH4Cl
(weak base) (salt)
NH3 + NH4Cl
(weak base) (salt)

19. Thank you