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AQUANAL® EduCase has been developed with the aim of enabling titrations to be carried out during school lessons. The case contains reagents for titrimetric determination of five typical constituents in the water which can be determined using four different types of titration: argentometric titration, acidimetric titration, complexometric titration and redox titration. The case comes complete with the entire equipment required for the determinations.
Titrations are carried out on a micro scale (5 ml - 10 ml test solution) so that both the amounts of reagents consumed and the volume of waste water produced are kept small. |
Calcium (Complexometric Titration)
Calcium is the main hardness constituent; its concentration is about four to five times as high as that of magnesium.
Calcium determination is effected by titration with EDTA; the indicator used is a calconcarboxylic acid trituration.
Subtracting calcium concentration from total hardness yields magnesium concentration.
Carbonate Hardness (Acid-Base Titration)
Carbonate hardness is part of total hardness; it denotes the proportion of calcium and magnesium ions which is present in solution as carbonate and
hydrogen carbonate. Carbonate hardness is also known as temporary hardness. It is determined by titration with hydrochloric acid; the end point of titration is
indicated by the Coopers indicator. Carbonate hardness is a measure of the sensitivity of the water to pH variations and is used in aquarium management
and fish breeding in particular.
Chloride (Argentometric Titration)
Chloride gets into the ground waters and surface waters when salts contained in the soil and rocks are washed out. It is determined by means of a
precipitation titration with silver nitrate, the indicator used is a dichlorofluorescein solution.
Oxygen (Redox Titration)
Oxygen gets into the water by way of diffusion from the air, for the most part however through photosynthesis of green aquatic plants.
It is indispensable for respira-tion of the aquatic organisms. The maximum concentration of oxygen dissolved in water varies greatly with temperature.
Oxygen concentration is determined by titration with sodium thiosulphate solution against starch solution.
Total Hardness (Complexometric Titration)
Total hardness is the sum of the calcium and magnesium ions in the water; it is measured in German degrees of hardness (0dH) or else in mg/l CaO.
Total hardness is determined by titration with EDTA; for end-point indication, use is made of a mixed indicator of eriochrome black T and methyl orange.
Total hardness is of significance, for example, in assessment of water for aquarium and fish breeding purposes as well as for dosing of detergents.
Ordering Information
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Product No.
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Product
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Add to Cart |
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37518
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AQUANAL® EduCase |
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37519
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AQUANAL® EduCase refill pack |
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37557
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AQUANAL® Ökotest |
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37566
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AQUANAL® Fishwater Lab |
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Provided with the case is a booklet describing the significance of the parameters; how to carry out the titrations; the chemical reactions;
suggestions on practice-relevant experiments; and a lot of other matters; also included are two concise instructions for use.
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