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1. Prepared by : Ali Muhamad + Muhamad Abuzed
Supervisor : Dr. Tablo AbdulrahimAhmed
Salahaddin University
College of Science
Biology Department
Third Stage
Water pH measuring
2023 - 2024

2. Presentation Main Points
✓ what's PH
✓ Acid and Base
✓ Number of PH
✓ Measurement of PH
✓ Calibration
✓ Importance of PH
✓ Pollution PH
✓ Reference

3. Is the term or parameter that
measuring the intensity of
acid or base.
Or measuring the
concentration of hydrogen
ions (H+).
As the water temperature
goes up, pH goes down .
What’s
PH

4. Cavendish (1766) the scientist
discovered hydrogen ion, so it
became clear that all acids contain
(H+) & after that the chemist found
that the reaction between acid &
base produce water.
Acid (H+) + (OH-) = water (H2O)
From above information it was
concluded that base contain (OH-.
Henry Cavendish
Discovery of
hydrogen ion H2

5. Acid: is the substance or
solution that dissociate to
give (H+).
Base: is the substance or
solution that dissociate to
give (OH-) hydroxyle group.
It was found that pure water
dissociated to give a
concentration of hydrogen
ion equal to (10-7 mole/ L
Acid
Base

6. pH scale: ranges from 0 to 14.
Neutral pH: 7 (pure water).
Acidic pH: less than 7.
Alkaline pH: greater than 7.
Each unit change represents a
tenfold difference in acidity or
alkalinity..
Number
of PH

7. By color indicator: it is possible
to determine pH value fairly
accurately by chossing an
indicator that give significant
color changes in the particular
range involved.
By using pH meter: electrode
constructed from glass which
develop a potential related to
H+ conc. Without interferrance.
Measurement
of PH

8. Calibration solutions: pH 4.01,
7.00, and 10.01 (for general use).
Two-point calibration: calibrate
at pH 7 and another point based
on the sample range..
Calibration
By Solution

9. 1) Calibration: the electrode with
buffer pH value (4,7,9).
Buffer:- is the standered.
• solution used for calibration.
2) Rinse: the electrode with distilled
water then immerse in the sample.
3) Read pH value: the accuracy of pH
Calibration
Steps

10. Measurement by pH meter
depend on
1. Types of procedures
2. Buffer solution that
used for calibration.
Depend
On

11. pH in Streams and Lakes
Maintaining a balanced pH in waters
is critical for aquatic health. Fish
and other organisms depend on
high-quality water with just the
right amount of dissolved oxygen
and nutrients.
Importance
of PH

12. A high or low pH can disrupt the
balance of chemicals in the water
and contaminants, causing toxic
conditions. Aquatic organisms can
experience problems with declining
populations and morbidity.
For this reason, pH is often sampled
by water quality scientists to
determine the health of streams,
lakes, rivers and groundwater.
Importance
of PH

13. Factors That Cause pH to Vary
Pollution is a large contributor
to the change in pH of natural
waters. Rainwater with a very
low pH, called acid rain, causes
environmental problems that
harm animals, plants and
humans.
Pollution
PH

14. In addition to acidity caused by
precipitation, contaminants
can enter water through
atmospheric deposition. Many
environmental laws and
regulations now are emerging
to manage and control the
harmful effects of
contaminants in water.
Pollution
PH

15. Thanks
References
• Oxford Dictionary of Biochemistry and
Molecular Biology (2 ed.), ed. Richard
Cammack, Teresa Atwood, Peter Campbell,
Howard Parish, Anthony Smith, Frank Vella, and
John Stirling, Oxford University Press 2006
Riddle, Peter (2013). “pH meters and their
electrodes: calibration, maintenance and use”.
The Biomedical Scientist. April: 202–205.
• Insert relevant scientific literature and
manufacturer specifications for pH meters and
calibration instruments.
Ltd, W G Pye and Co (1962). “Potentiometric pH
Meter”. Journal of Scientific Instruments. 39 (6)