Hard Water

HARD WATER

Soap = removes hardness/can measure degree of hardness

Scum = soap + hard water

Lather = soap + soft water

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Limestone 

• calcium carbonate
• dissolves in rain water to make water hard

CaCO₃ + H₂O + CO₂ ----> Ca(HCO₃)₂ 

Limescale/Scale

Washing Soda/Sodium Sulphate

• softens water
• removes hardnes/Calcium ions - white percipitate of calcium carbonate

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Permanently Hard - not soften by boiling - due to Calcium Sulphate - Gypsium

Temporary - softens on boiling as Calcium hydrogen carbonate Ca(HCO₃)₂