Title: Standard operating procedure for
determination of specific gravity of liquid sample by using Pycnometer.
1.0
OBJECTIVE:
To lay down a procedure for determination
of specific gravity of liquid sample by using Pycnometer.
2.0
SCOPE:
This SOP shall be applicable to Q.C
Dept.
3.0
RESPONSIBILITY:
3.1
Doing: Q.C Analyst.
3.2
Checking: Q.C-Manager.
4.0
ACCOUNTABILITY:
4.1
Head of the Q.C Department.
5.0
MATERIAL AND EQUIPMENT:
5.1
Pycnometer.
5.2
Sample.
5.3
Purified water.
6.0
PROCEDURE:
6.1
Make sure that the instrument is clean.
6.2
Operate the apparatus according to SOP.
6.3
Ensure the solid to be tested must be weigh carefully.
6.4
Ensure that the liquid to be tested has been thoroughly, but
gently stirred and that any entrained air has been removed.
6.5
Weigh the empty Pycnometer with stoppered on the analytical
weighing balance i.e. W1.
6.6
Fill the exact volume of your liquid sample solution into
the Pycnometer carefully. It should come nearly to the rim of the Pycnometer.
6.7
Insert the stopper and tapping the sides gently to remove
the air bubble.
6.8
Firmly and evenly seat the stopper on the Pycnometer flask.
A small amount of liquid should appear from the hole in the stopper.
6.9
Dry the sides and weigh the filled Pycnometer with stoppered
again on the analytical weighing balance i.e. W2.
6.10
Record the observations into the annexure-2.
6.11
Note down the temperature of the sample.
6.12
Calculate the sample weight by using formula:
Sample weight (g) = (wt. of filled
Pycnometer with stopper) – (wt. of empty Pycnometer with stopper)
6.13
Calculate the specific gravity of the liquid sample by using
formula:
Specific
gravity of sample = ___Density of the substance___
Density of the purified water
Or
Specific
gravity of sample = ________Weight of the substance_______
Weight of an equal volume of water
6.14
Precautions:
6.14.1
Be certain to use the
known density value at the correct temperature.
6.14.2
Do the same for the
procedure in the liquid unknown. Calculate the density of the unknowns.
7.0
REVISION LOG:
|
Revision No. |
Effective Date |
Reason |
|
00 |
|
New
SOP |
8.0
REFERENCES:
8.1
Not Applicable.
9.0
ANNEXURES:
Annexure
1: Specific gravity of water at different
temperatures.
Annexure
2: Observations and calculations of
specific gravity by using Pycnometer.
Annexure: 1
Specific gravity of water at different
temperature
|
Specific
gravity of purified water (g/cm3) |
At
temperature (oC) |
|
0.9957 |
30oC |
|
0.99602 |
25oC |
|
0.9982 |
20oC |
|
0.9997 |
10oC |
|
1.0000 |
4oC |
|
0.9998 |
0oC |
Annexure: 2
Observations and calculations of
specific gravity by using Pycnometer
|
OBSERVATIONS AND CALCULATIONS OF
SPECIFIC GRAVITY BY USING PYCNOMETER
Weigh
the empty Pycnometer with stopper = W1 = _____________g. Weigh
the filled Pycnometer with stopper = W2 = ______________g. Sample weight (g) = (wt. of filled Pycnometer
with stopper) – (wt. of empty Pycnometer with stopper) Specific
gravity of the liquid sample by using formula: Specific gravity of sample = ___Density of the
substance___ Density
of the purified water Or Specific gravity of sample = ______Weight of the
substance_______ Weight of an equal volume of
water
Remarks:
_______________________________________________________________ _______________________________________________________________________ |