 |
|||
|
|
|||
| ||||||||||
|
|  MIL-D-70436(AR)
second 100 ml calibrated volumetric flask and diluted to the mark
with distilled water. Transfer a portion of this solution to a
acorex glass spectrophotometric cell having a width of 1
centimeter (cm) and a similar cell containing saturated ammonium
acetate solution of the same concentration as the sample in the
final dilution. Since the cell which holds the normal lead
styphnate is not identical with the reference cell, correct the
absorbance obtained as the two cells scatter and absorb. TO do
this, both cells shall be filled with ammonium acetate solution
measure at a wave length of 410 millimicrons with absorbance of
the cell which originally contained the normal lead styphnate
solution. Calculate the percentage of normal lead styphnate in
the sample shall be calculated on a dry basis as follows:
where:
A
=
Absorbance of basic lead styphnate solution.
B
=
Absorbance of ammonium acetate solution.
D
=
Width of corex cell, cm.
W
=
Weight of dried sample.
Spectrophotometric factor. To determine the spectrophoto-
F
=
metric factor (F) weight a 0.5 gm sample of pure lead
styphnate. Transfer the lead styphnate quantitatively
with 50 to 100 ml of diluted water to a 500 ml volumetric
flask, add 30 ml of saturated ammonium acetate solution to
the solution in the flask and dilute to mark with
distilled water. Using aliquots of the solution, prepare
five solutions of lead styphnate ranging in concentration
from .5 to 2.5 mg per 100 ml. Determine the absorbance of
each solution at 410 millimicrons. Divide concentrations
of lead styphnate for each of the solutions by its
corresponding absorbance value. The average of the five
quotients thus obtained shall be used as the spectrophoto-
metric factor (F) for the lead styphnate.
4.5.5.3 Tetracene. The wet residue obtained in the
determination of lead styphnate shall be washed three times with
alcohol, dried in an oven maintained at 60 degrees C plus or minus
5 degrees C for 30 minutes, cooled in a desiccator and weighed.
The dried residue in the crucible shall be transferred to a 125 ml
beaker with a stream of water, 25 ml of water shall be added, and
the contents of the beaker boiled on a hot plate for five
minutes. The contents of the beaker shall be poured into the same
crucible, and the residue in the crucible washed three times with
boiling water, and finally with alcohol. The crucible and
|
|
Privacy Statement - Press Release - Copyright Information. - Contact Us |
Click
here for thousands of PDF manuals