TM 10-6630-245-13&P
WARNING
SULFURIC ACID REAGENT
Corrosive acid. May cause permanent damage to eyes, severe bums, and ulcerations on skin.
Inhalation may damage respiratory tract. Do not ingest or allow contact with skin or eyes. Avoid
breathing vapors. In case of contact, flush eyes or skin with plenty of water. For eyes, call
medic. In case of ingestion, DO NOT induce vomiting. Give milk of magnesia and large amounts
of water. Follow with milk or raw egg whites beaten in water. Call medic immediately. In case of
inhalation, remove victim to fresh air.
(7)
Uncap the sample bottle(l). Using the 0.5 ml dropping pipet(9) add 0.5 ml of sulfuric acid(2). Recap the
bottle(1) and mix by shaking until the precipitate is completely dissolved. The sample is now "fixed."
(8)
Using the sample just treated, fill the 50 ml titration flask(3) to the 50 ml line. Cap the flask(3).
WARNING
THIOSULFATE SODIUM SOLUTION
For test purposes only. May be harmful if swallowed. May irritate eyes, skin and mucous
membranes on contact. Do not ingest or allow contact with skin or eyes. Avoid breathing
vapors. In case of contact, flush eyes with water for at least 15 minutes. Get immediate medical
attention. Wash skin with soap and water. In case of ingestion, get immediate medical attention.
In case of inhalation, remove victim to fresh air.
(9)
Fill the mini burette(6) with standard sodium thiosulfate solution(4). Follow the steps below.
NOTE
The mini burette consists of a graduated barrel with a tipped plunger that slides freely back and
forth inside the barrel. The barrel is marked with 20 numbered major divisions. Each major
division is divided into five unnumbered subdivisions. All readings are made where the bottom
of the plunger tip intersects the graduated scale.
(a)
Remove the cap from the titration
reagent
sodium
thiosulfate
solution(4). Insert the open end(3,
fig. 2-14) of the mini burette below
the liquid. The plunger(l) of the mini
burette should be pushed all the
way in so the plunger tip(2) is
resting on the bottom of the burette
barrel(4).
(b)
Fill the burette by pulling the
plunger(l) up until the plunger tip(2)
is lined up with the zero mark on the
graduated scale(5). Be sure to keep
the tip in the titration solution. Wipe
the outside of the mini burette with
a tissue before titrating. Recap the
bottle
of
sodium
thiosulfate
solution(4, fig. 2-10) immediately
after filling the burette.
(10)
Titrate with standard sodium thiosulfate
solution(4) until the brown iodine color has
nearly disappeared as follows.
(a)
Remove the cap from the titration
flask(3).
Figure 2-14. Mini Burette.
2-36
