Megamarko94
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testing hardness of water..
way's to test ammount of Ca2+ and Mg2+ ions in water...
[Edited on 29-5-2011 by Megamarko94]
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azo
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buy a cf meter
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redox
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It is easy to buy hardness test strips online or in pool stores or some other place. Alternatively, you could see the below webpage for a quantative
approximation
( http://www.ehow.com/how_4843662_test-water-hardness.html ) .
If you need to remove these hard ions, you could pass the water through an ion exchange resin, which can be had somewhat cheaply.
My quite small but growing Youtube Channel: http://www.youtube.com/user/RealChemLabs
Newest video: Synthesis of Chloroform
The difference between chemists and chemical engineers: Chemists use test tubes, chemical engineers use buckets. |
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unionised
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Perhaps it's different across the pond, but most dish washing liquids here are soap-less detergents and so they wouldn't work for that test.
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blogfast25
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Quote: Originally posted by unionised  | | Perhaps it's different across the pond, but most dish washing liquids here are soap-less detergents and so they wouldn't work for that test.
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No, all washing up liquids here are detergents, not actual soaps.
But devising a quick comparative test with a dilute solution of a real soap (use distilled or dionised water for that) is easy to do.
For a precise determination of Ca2+ and Mg2+ concentrations (the ions that cause water hardness) you need to titrate your water with EDTA or NaEDTA
using various complexing indicators like Eriochrome T. You would need to look that up on the net but it’s not for the inexperienced/ill-equipped.
[Edited on 30-5-2011 by blogfast25]
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AJKOER
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For a crude comparative tool, prepare fixed sized samples of varying degrees of artificially created hard water to which you add a fix quantity of a
base (Ammonia, soap,..).
The hardness in water can be due to soluble bicarbonates salts of Calcium and Magnesium, as an example.
CaCO3 + CO2 + H2O <==> Ca2+ + 2HCO3-
So upon adding a base, the equilibrium is moved to the left with a possible colloidal suspension of hydroxides:
2 NH4OH + Ca(HCO3)2 ---> Ca(OH)2 (s) + 2 NH4(HCO3)2
Note: excess base may re-dissolve the suspension forming, for example, ammonia complexes.
A direct visible relative comparison of actual to prepared samples is one possible crude measure. Alternately, wait for the suspension to precipitate
and place in a thin long tube to measure relative total hydroxide concentration.
While imprecise, this process does attempt to directly assess the problem, namely the visible magnitude of the total of all salts soap scum.
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azo
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ca mg cations precipitate from water when treated with sodium bicarbonate,
tri sodium phospate, mono sodium phosphate,or sodium carbonate forming an insoluble complex.
Unlike edta,stpp which sequester hardness ions
regards azo
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