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Water Hardness. Prepared by Anna Danczowska -Burdon. What cause s water hardness??. Water hardness is caused by the presence of salts dissolved in water, primarily calcium and magnesium. It causes the formation of boiler scale during water boiling and bad soap foaming.
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Water Hardness Prepared by Anna Danczowska-Burdon
What causes water hardness?? Water hardness is caused by the presence of salts dissolved in water, primarily calcium and magnesium.It causes the formation of boiler scale during water boiling and bad soap foaming.
How can we divide water hardness?? • carbonate hardness – also called temporary water hardness is caused by the presence of carbonates, hydrocarbonates and hydroxides of calcium and magnesium. • Noncarbonate hardness – caused by the presence of Ca2+, Mg2+ of other cations and anions like: Al3+, Fe2+, Fe3+, Cu2+, Cl-, SO42-, NO3-, which do not decompose and do not precipitate during boiling water. • General water hardness – is the summary content of calcium, magnesium and other ions
Temporary water hardness • Caused by the presence of hydrocarbonates, carbonates and hydroxides of calcium and magnesium. It can be removed by water boiling. • Ca(HCO3)2 → CaCO3+ H2O + CO2 • Mg(HCO3)2 → MgCO3+ H2O + CO2
Howcan we determinewaterhardness?? • Clark’s Method, • Blacher’s Method, • Warta-Pfeifer Method, • method using EDTA (versenate) • separate determination of calcium and magnesium ions