LaMotte AM-21 Water Pollution Detection Outfit - Manual (Page 18)

Overhead Projection Demonstration
Quantity Contents Code
15 mL *Phenolphthalein Indicator, 1% *2246-E
30 mL *Carbon Dioxide Reagent B 4253-G
1 Test Tube, 5-10-12.9-15-20-25 mL,
glass, w/cap 0608
1 Direct Reading Titrator, 0-50 Range 0380
1 Demonstration Stage, three cell 1039
1 Spatula 0691
WARNING: Reagents marked with a * are considered to be potential health hazards.
To view or print a Material Safety Data Sheet (MSDS) for these reagents see MSDS CD
or www.lamotte.com. To obtain a printed copy, contact LaMotte by email, phone or fax.
Read the LaMotte Direct Reading Titrator Manual before proceeding.
Procedure
1. Place the demonstration stage (1039) on the overhead projector and
turn on the projector light.
2. Fill the test tube (0608) to the 20 mL line with sample water and transfer
this liquid to a cell on the demonstration stage (1039).
3. Add two drops *Phenolphthalein Indicator, 1% (2246) and gently stir
the contents of the cell with spatula (0691).
4. If the solution turns red, no free carbon dioxide is present. If the solution
is colorless, it is titrated to determine the amount of carbon dioxide
present.
5. Fill the Direct Reading Titrator (0382) with *Carbon Dioxide Reagent B
(4253).
6. The Titrator is held by hand over the cell. Discharge one drop of the
reagent at a time from the titrator. Stir the mixture after the addition of
each drop. Add the titration reagent until a permanent pink color is
produced and persists for at least 30 seconds. Read the test result directly
from the scale where the large ring on the Titrator meets the Titrator
barrel. Record the result as ppm Carbon Dioxide.
NOTE: The accuracy of the test method for carbon dioxide is reduced with
the overhead projection demonstration because of the increased
exposure of the sample to the air.
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