2.1 Hard Water Flashcards
Why does hard water use more soap to produce lather?
Hard water contains dissolved compounds that react with soap to form an insoluble solid called scum
What is scum?
The insoluble solid formed when hard water reacts with soap
What doesn’t react with hard water to form scum?
Soap less detergents
What is the difference between soft and hard water?
Soft water lathers easily with soap whereas hard water does not
How does water become hard?
In the rivers, when the water becomes in contact with sedimentary rocks, some compounds dissolve
What compounds are found in hard water?
Calcium and magnesium compounds
What type of hard water produces scale when it is heated?
Temporary
What is formed when temporary hard water is heated?
Scale
What is scale?
An insoluble solid produced when temporary hard water is heated
Name 3 places where scale can be deposited
- kettles
- pipes
- boilers
What does scale cause?
A reduction in the efficiency of heating systems and blockages
What is the difference between scum and scale?
Scum is formed when soap reacts with hard water. Scale is formed when temporary hard water is heated
Name 3 advantages of drinking hard water?
Calcium:
•is good for our health
•develops strong bones and teeth
•reduces the risk of heart disease
What compounds are found in temporary water?
Calcium or magnesium carbonate
Ca or Mg (HCO3)2
What compounds are found in permanent hard water?
Calcium or magnesium sulphate
Ca or Mg (SO4)
