Hard And Soft Water Flashcards
Soft water form what with soap
Lather
Hard water reacts with soap to form what
How can we form lather from this
Scum
Add more soap
True or false?
Soapless detergents form scum
False!!!
Hard water contains dissolved compounds. What are they
Magnesium or calcium
How does water turn hard
Acidic rain dissolved limestone leaving calcium to be dissolved in water
What are the two types of hard water
Permanent hard water
Temporary hard water
How do you know if water is permanently hard
Remains hard when boiled
How do you know if water is temporary hard
Softened by boiling
What does temporary hard water cost brain
Hydrogencarbonate ions (HCO3-)
What happens to hydrogencarbonate ions form when heated
Decompose producing carbonate ions which react with calcium and magnesium- form precipitates
Name a disadvantage to using hard water
Increase costs as more soap needed
What is a disadvantage of temporary hard water
When heated produces scale- reduces efficiency for heating systems and kettles
What are the pros to hard water
Calcium compounds good for bones and teeth
Calcium reduces heart disease
How can hard water be made soft
Basically how to remove calcium and magnesium ions
Adding sodium carbonate- reacts with calcium and magnesium to form calcium carbons and magnesium carbonate
Commercial water softeners e.g. Ions exchange columns containing hydrogen of sodium ions. Replace hard water ions when passed through
