9.4 - Estimation of Dissolved Oxygen by Redox Titration (Leaving Cert Chemistry): Flashcards
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Method used to estimate dissolved oxygen by redox titration
Method used to estimate dissolved oxygen by redox titration
Winkler's method
What D.O. stands for in water analysis
What D.O. stands for in water analysis
Dissolved oxygen
First reagent added in Winkler's method
First reagent added in Winkler's method
Manganese (II) sulfate
Second reagent added in Winkler's method
Second reagent added in Winkler's method
Alkaline potassium iodide
Titrant used in Winkler's method
Titrant used in Winkler's method
Sodium thiosulfate
Molarity of sodium thiosulfate used
Molarity of sodium thiosulfate used
0.005 M
Units for dissolved oxygen concentration
Units for dissolved oxygen concentration
Parts per million (ppm)
Colour of first precipitate formed
Colour of first precipitate formed
White
Colour of second precipitate formed
Colour of second precipitate formed
Brown
Role of sulfuric acid in Winkler's method
Role of sulfuric acid in Winkler's method
Dissolves precipitate and releases iodine
Solution colour after adding sulfuric acid
Solution colour after adding sulfuric acid
Golden-brown
Indicator used near endpoint
Indicator used near endpoint
Starch indicator
Endpoint observation in Winkler's titration
Endpoint observation in Winkler's titration
Blue colour disappears
Volume of iodine solution pipetted
Volume of iodine solution pipetted
50 cm³