LaMotte OAKITE ALKALINE TEST KIT OKT 9205 User Manual

Page 9

PROCEDURE 123

DETERMINING FREE AND TOTAL ALKALI IN CLEANING SOLUTIONS

(THIS PROCEDURE REPLACES PREVIOUS OAKITE PROCEDURE 13)

Test Kit: - OAKITE ALKALINE TEST KIT (CODE OKT 9205)

Reagents and Equipment:

Code

Quantity

Description

OKT 6130-J

100 ml

1 N Hydrochloric Acid

OKT 6131-J

100 ml

0.1 N Hydrochloric Acid

OKT 2246-G

25 ml

Phenolphthalein

OKT 2207-G

25 ml

Bromcresol Green

OKT 2292-G

25 ml

Methyl Red

0376

Direct Reading Titrator; 0-1 ml

0778

Titration Tube marked at 5, 10 and
15 ml, with cap

0354

Plastic dropper marked at 1 ml

Step 1:

Using the 1 ml dropper, pipet the appropriate sample volume of Oakite solution
listed in the table below into the empty titration tube. Add water to this solution
until the volume is at least to the 5 ml mark. For 5 and 10 ml sample volumes,
use the graduations on the titration tube. No water need be added. For
appropriate sample volumes see notes 4, 5 and 6 below.

Step 2:

Add 1 or 2 drops of Phenolphthalein Indicator. Swirl to mix. The color will be
red. Place the cap on the titration tube.

Step 3:

Fill the Direct Reading Titrator* to the zero mark with 1N Acid. Insert tip of
Titrator into the central hole in the titrating tube cap. While holding the Titrator
assembly in one hand, slowly depress the plunger of the Titrator with the other
hand to dispense the titrating solution. Swirl the solution gently after each drop
has been added. When the red color of the solution disappears completely,
stop any further movement of the plunger. Record the reading on the Titrator in
ml. Call this Titration A.

Step 4:

Into the mixture from Step 3, add 1 or 2 drops of Bromcresol Green Indicator.
Swirl to mix. The color of the solution will be blue.

Step 5:

Again, fill the Direct Reading Titrator to the zero mark with 1N Acid and titrate
the blue solution until the color changes to a distinct yellow. Record the reading
on the Titrator in ml. Call this Titration B.

Calculations:

A + B = Total Alkali
A - B = Free Alkali
A - B = Ratio of Free Alkali
A + B Total Alkali

TK 123

(con tin ued)