Determination of PH of Water Ample

Determination of pH in Given Water Sample
Objectives
Objectives of this lab includes:
 To get knowledge of pH in water

 To learn about the role of pH in water quality
 To understand the precautions and procedures involved in the determination of pH in
water
Definition
pH stands for the power of hydrogen ions in the water or in any solution. pH (potential of
hydrogen) is a numeric scale used to specify the acidity or basicity of an aqueous solution.
Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7
are basic. Pure water is neutral, at pH 7 (25 °C).Its full scale is of 14. The normal drinking
water has pH of ranging from 6.5 to 8.5.
The mathematical definition of pH is as, the negative logarithm of concentration of hydrogen

ions.
pH = - log[H+]
Significance:
 Drinking water
Measurement of pH of water is one of the most important objective in water treatment
of waste water. When we treat the water for the drinking purpose, there is a prescribed
value of pH by the competent authorities such as PEQS (Pakistan Environment
Quality Standard), etc. According to these authorities the pH of drinking of water
should be ranging from 6.5 to 8.5.
 Waste water
Similarly, there are guidelines given for the waste water. According to the PEQS and
other authorities the, pH of the water should be range from 6 to 9. This range is very
important because if the water does not have this range of water it will cause harm to
the aquatic life in lakes, rivers which ultimately the loss to human beings.
38 | P a g e
 In treatment of water
When we treat the water with chemicals or techniques the pH of water changes from
its original value and then we have to bring the value of pH of water back to its
standard values and for this we take and note the value of pH before and after the
experiment. By this the pH of the water recovered by adding some alkali or acid to
balance the pH. That’s why careful attention to pH control is necessary at all stages of
water treatment to ensure satisfactory water clarification and disinfection.
 Chlorination
For effective disinfection with chlorine, the pH should preferably be less than 8.0. The
pH of the water entering the distribution system must be controlled to minimize the
corrosion of water mains and pipes in household water systems. Failure to do so can
result in the contamination of drinking-water and in adverse effects on its taste, odor
and appearance. Extreme pH values can result from accidental spills, treatment
breakdowns and insufficiently cured cement mortar pipe linings.
 Health effects
The pH of the water has very serious impact on our health and daily routine. If the
water is acidic then it has bad effects on health and if the water is alkaline then it’s
some quantity is good for health. For example, if your water is alkaline, you get
healthy minerals in it, if your water is acidic, you can absorb toxins like mercury from
it.
NEQS Guidelines
According to these NEQS and PEQS guidelines, the pH of drinking of water should be
ranging from 6.5 to 8.5.
According to these NEQS and PEQS guidelines, the pH of wastewater should be ranging
from 6 to 9.
pH Measurement
Collection, Sampling and Storage
 Container: For pH sample gas-tighten bottles should be used. Bottles should be

rinsed thoroughly with sample water before filling. Bottles should be of plastic.
39 | P a g e
 Storage: Samples should preferably be analyzed as soon as possible directly after
sampling. But it can be stored at 4 degrees Celsius.
 Holding Time: sample can be stored for 3 days at 4 degrees Celsius.
Interferences
pH of water depends on following parameters so before testing the sample following

parameters should be considered for pH of water sample
 Buffering Capacity of water
 Temperature dependent
 Extremes can effect palatability, corrosive effects, ammonia toxicity, metal solubility
etc.
Materials and Reagents Required
 Two water samples

 pH meter
 Wash bottle
 Distilled water
 Calibrated flask
 Tissue paper
 Calibration solutions (acidic and basic buffers)
 Water sample
Procedure
1. Take a calibrated pH meter.

2. Check its calibration by using the buffer solutions both acidic and basic.
3. Then wash the probe of pH meter with the distilled water.
4. Now take given sample of water and check its pH by touching the probe of pH meter
with the surface of water.
5. Perform the experiment at least three times.
40 | P a g e
Observation
The value of pH obtained using pH meter is 7.61.
Results
The value of pH obtained is 7.61.
Comments
We have performed the experiment of pH determination. We have learned about the pH, its
importance and significance in water testing and water quality. We have also learned to use
the pH meter and precautions and standardization of the meter, which is a vital instrument in
pH determination nowadays.
The value of pH of water sample which we have taken for experiment is in neutral range and
in satisfy the PEQS and NEQS standard value.
41 | P a g e

Determination of PH of Water Ample

Uploaded by

Copyright:

Available Formats

Determination of PH of Water Ample

Uploaded by

Document Information

Original Description:

Original Title

Copyright

Available Formats

Share this document

Share or Embed Document

Sharing Options

Did you find this document useful?

Is this content inappropriate?

Copyright:

Available Formats

Determination of PH of Water Ample

Uploaded by

Copyright:

Available Formats

Determination of pH in Given Water Sample

Objectives of this lab includes:

 To get knowledge of pH in water

The mathematical definition of pH is as, the negative logarithm of concentration of hydrogen

Collection, Sampling and Storage

 Container: For pH sample gas-tighten bottles should be used. Bottles should be

pH of water depends on following parameters so before testing the sample following

 Buffering Capacity of water

Materials and Reagents Required

 Two water samples

1. Take a calibrated pH meter.

The value of pH obtained using pH meter is 7.61.

The value of pH obtained is 7.61.

You might also like