Hard And Soft Water Flashcards
Why does hard water make soap less ergonomic?
Because the Ca2+ ions react with the soap to form a solid precipitate (scum). All of the Ca2+ ions need to be reacted with before a lather can be made, meaning more soap needs to be used.
How is water hardened?
When in a river it can run over rocks like gypsum,limestone and chalk. The magnesium and calcium ion compounds are dissolved in the water.
Alternatively the compounds can be dissolved in rainwater.
Why does scale reduce efficiency of kettles?
Because it surrounds the hearing component of the kettle and acts as a thermal insulator, allowing less heat to be transferred to the water- it takes longer to boil.
How does washing soda soften water?
Sodium carbonate( Na2CO3) . The carbonate ions react with the Ca2+ and Mg2+ ions to form solid precipitates calcium carbonate and magnesium carbonate.
The ions are no longer present in the water so it if soft.
What makes temporary hard water this way?
The fact that it contains hydrocarbonate ions (HCO3 2-). When heated these decompose to form carbonate ions, these react with Mg2+ and Ca2+ to form solid precipitates CaCO3 and MgCO3
What are two health benefits of hard water?
Hardens teeth and bones
Reduces risk of heart disease
How does an ion exchange column soften the water?
Calcium ions in the water are exchanged for the sodium ions in the resin
