Karteikarten
Water
Karten in diesem Stapel (9)
- 1Water that lathers easily with soapsoft water
- 2How is scum formed?calcium/magnesium ions in hard water react with soap producing the insoluble solid
- 3How is scale formed?when temporary hard water is heated, insoluble magnesium/calcium carbonate is formed
reduces efficiency of heating systems - 4How is water made safe to drink?Purified by filtration (removes solid) and by adding chlorine to kill bacteria
- 5How to test for hardnessuse equal amounts of water, add identical amounts of soap, shake and measure height of froth.
Higher froth= softer the water (proportional relationship) - 6How do you soften temporary hard water?-when heated, hydrogencarbonate ions decompose to produce carbonate ions, water & CO2
-these carbonate ions react with magnesium/calcium ions in water, forming magnesium/calcium carbonate which are deposited as scale - 7How to remove hardness in water using iron exchange columna) Use an ion exchange column packed with resin containing sodium ions
b) when hard water is passed through, Ca/Mg ions become attached to resin
and they are swapped for sodium ions
c) sodium ions don't react with the soap - 8How to remove hardness in water by precipitating out ionsAdd Sodium Carbonate which causes the Ca/Mg ions to form calcium carbonate & magnesium carbonate precipitates (a solid that does not dissolve)
- 9Equation for softening of temporary hard water2HCO₃ (aq) ---> CO₃ (aq) + H₂O (l) + CO₂ (g)
Informationen
- Beschreibung
- GCSE Chemistry (3) Further) Karteikarten am Water, erstellt von Alex C am 11/06/2016.
- Erstellt von
- Alex C · Jun 2016
- Aktualisiert
- 12 Jun 2016
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