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1. The pH meter
GROUP 1
JOBAH B. AGUSTIN
JANINE CLARISSE M. ANTARAN
YE SHA BIANCA O. BUSTAMANTE
HONNAH YHOBEL Q. ROMANDI
JAYBE CHRISTIAN C. CADION
BIOTECHNIQ
UES

2. TABLE OF CONTENTS
Introduction to pH
meter
Acid Base
Use of the pH meter
Importance of pH
meter
1
3
5
2
4
Buffer

3. Introduction to
pH meter
1

4. ● an electronic device that
measures the activity of
hydrogen ions (acidity or
alkalinity) in solution.
● A pH meter is fundamentally
made up of a voltmeter
connected to a pH-responsive
electrode and a reference
(unvarying) electrode.
pH meter

5. ● While on the faculty of the California
Institute of Technology, he invented
the first commercially effective
electronic pH meter in 1934
● He named it the “acidmeter”
History
Arnold O. Beckman

6. ● It contained all of the necessary
components, allowing scientists to test
acidity correctly and quickly.
● It was purposely for measuring the
acidity in citrus
History

7. Parts

8. Acid Base
2

9. ● An acid is any hydrogen-containing substance that is capable
of donating a proton (hydrogen ion) to another substance.
 Acids are known to turn blue litmus red.
● A base is a molecule or ion able to accept a hydrogen ion
from an acid.
 Bases are known to turn red litmus blue.
Acids and Bases

10. • 𝑯𝟑𝑶+ is called a hydronium ion, and it makes things
acidic.
• 𝑶𝑯− is called a hydroxyl ion and it makes things basic.
Note: Sometimes people write 𝑯+ as a shorthand for
𝑯𝟑𝑶+
and that can cause confusion, because sometimes
when people write 𝑯+ they really do mean only 𝑯+ and
not 𝑯𝟑𝑶+
What makes a substance acidic or basic?
𝟐 𝑯𝟐𝑶⇌ 𝟏 𝑯𝟑𝑶+
+ 𝟏 𝑶𝑯−

11. • That happens when the hydroniums and the
hydroxyls are out of balance.
 If there are more positively charged hydroniums
than negatively charged hydroxyls, then the
substance is acidic.
 If there are more negatively charged hydroxyls
than positively charged hydroniums, then the
substance becomes basic.
How does something become acidic or
basic?

12. ● Vinegar, a weak acid, has a chemical formula of
𝐶𝐻3𝐶𝑂𝑂𝐻. When dissolved in water, it becomes 𝐶𝐻3𝐶𝑂𝑂−
and 𝐻+
.
● Lye, a strong base with the chemical formula
𝑁𝑎𝑂𝐻 (sodium hydroxide). If we add NaOH to water, it
dissociates into 𝑁𝑎+ and 𝑂𝐻−.
Exampl
e

13. • Because they are out of balance.
Why are strong acids and strong bases so
nasty?

14. Buffer
3

15. How can
organisms whose
bodies require a
near-neutral pH
ingest acidic and
basic substances?

16. ● A buffer is a solution that can
resist pH change upon the
addition of an acidic or basic
components.
What is Buffer?

17. ● It is able to neutralize small
amounts of added acid or base,
thus maintaining the pH of the
solution relatively stable.
How does Buffer work?

18. Why is it important
to neutralize the pH
level of a
substance?
“To low and too much is
bad.”

19. A weak acid and its conjugate base OR A weak base
and its conjugate acid
Example:
● Acetic acid (weak organic acid) and a salt containing
its conjugate base
 acetate anion, such as sodium acetate
What is Buffer composed of?

20. ● Pyridine (weak base) and a salt containing its
conjugate acid
 pyridinium cation, such as Pyridinium Chloride.
● Ammonia (weak base) and a salt containing its
conjugate acid
 the ammonium cation, such as Ammonium
Hydroxide

21. ● Acidic buffer
 Acid buffer solutions have a pH less than 7. It is
generally made from a weak acid and one of its
salts.
● Alkaline buffer
 Alkaline buffer solutions have a pH greater than 7
and are made from a weak base and one of its
salts.
Types of Buffer Solution

22. ● Maintaining a constant blood pH is critical to a
person's well-being.
● Antacids which combat excess stomach acid.
● Over-the-counter medications work similarly to blood
buffers capable of absorbing hydrogen and
moderating pH, bringing relief to those that suffer
"heartburn" from stomach acid after eating.
Applications of Buffer in Real Life

23. Use of the
pH meter
4

24. The Use of pH meter
 The pH meter is used for determining the
concentration of hydrogen ions [H+] in a
solution.
 This equipment, provided it is carefully
used and calibrated, measures the acidity
of an aqueous solution.
 pH meters are sometimes called pH
analysers, pH monitors or potentiometers.

25. Purpose of the Equipment
 The pH meter is commonly used in any
field of science related to aqueous
solutions.
 It is used in areas such as agriculture,
water treatment and purification, in
industrial processes such as
petrochemicals, paper manufacture, foods,
pharmaceuticals, research and
development, metal mechanics, etc.

26. Purpose of the Equipment
 In the health laboratory, its applications are
related to the control of culture mediums
and to the measurement of the alkalinity or
acidity of broths and buffers.
 In specialized laboratories, diagnostic
equipment microelectrodes are used to
measure the pH of liquid blood
components.

27. Importance of
pH meter
5

28.  Essential for food
processing, in which it
is used to insure that
food products have an
adequate acidity level
that will prevent
growth of foodborne
pathogens.
Importance of pH meter
 To obtain more
accurate pH
measurements.
 It determines the product
quality or monitors
chemical reactions.
Ensures safety and quality
especially in food and
beverages.

29.  It is an important instrument used to give rise to more
accurate information in various applications. Such as
soil measurements in agriculture, water quality for
municipal water supplies, swimming pools,
environmental remediation; manufacturing, healthcare
and clinical applications such as blood chemistry; and
many other applications.
Importance of pH meter

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