3.2 Water Flashcards
What are the two types of water?
Hard and soft
Where is water hard?
Yorkshire, London and South East England
Where is water soft?
Lancashire, North Wales and the Lake District
What does Water hardness depend on?
The mineral ions dissolved into the water from the rocks
What ions make water hard?
Calcium and Magnesium
What are advantages of hard water?
Calcium strengthens bones and teeth
Calcium may also reduce the risk of heart disease
What are the two types of hard water?
Temporary
Permenant
What is temporary hard water?
High concentration of hydrogen carbonate ions
They decompose on heating
What is permanent hard water?
High concentration of sulfate ions
They don’t decompose when heated
What are two methods of removing water hardness if the water is temporary?
Boiling the water
Soap solution
What is created when hard water is heated?
Soft water and scale
Removing calcium, magnesium and hydrogen carbonate ions
What can scale do?
Reduce efficiency in kettles, boilers and pipes
What happens if you add soap solution to soft or hard water?
Soft - Lathers
Hard - Little Lather
What does hard water produce when reacted with soap solution?
Soft water and a precipitate called scum
What are two methods of removing water hardness if the water is permanent?
Adding sodium carbonate
Ion exchange column